Articles of manufacture comprising nanocellulose elements

ABSTRACT

The present invention provides formulations comprising a suspension of nanocellulose (NC) elements and a drying/dispersal additive selected from the group consisting of temperature-responsive polymers, small molecule additives in volatile systems, and blocking agents and methods of preparing such formulations, and further provides NC-containing materials, composite materials and useful articles of manufacture made therefrom.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/834,521, filed Jun. 7, 2022, which claims the benefit of U.S.Provisional Application No. 63/208,577 filed Jun. 9, 2021, U.S.Provisional Application No. 63/219,686 filed Jul. 8, 2021, and U.S.Provisional Application No. 63/309,730 filed Feb. 14, 2022. The entirecontents of the above applications are incorporated by reference herein.

FIELD OF THE INVENTION

This application relates to nanocellulosic materials.

BACKGROUND OF THE INVENTION

Cellulose, the main building block for wood and plant fibers, is anabundant resource for the paper, textile, and chemical industries. It isa high molecular weight homopolymer of 1,4-linked β-D-glucopyranoseunits in which each unit is rotated 180° with respect to adjacent units.The monomeric glucopyranose units each contain three hydroxyl groups,which present themselves on alternating opposite sides of the polymerbecause of the rotational pattern of their linear arrangement within thepolymer. The alternating orientation of the hydroxyl groups along thelength of the cellulose molecule allows one strand of cellulose to formhydrogen bonds readily with adjacent strands of the polymer. Thesehydrogen bonds permit the formation of multistrand composites that arestable, strong, and tightly cohesive.

In biological systems, individual polymeric cellulose molecules formlarger units with similar molecules. Biosynthesis within a plant canallow about thirty-six individual molecules to be bound togethercompactly, thereby forming the most basic building blocks of the plant'scell wall. These building blocks are called elementary fibrils (alsotermed microfibrils). The elementary fibrils, formed during thebiosynthesis of cellulose in the biological entity, are about 5 nm indiameter and can be several micrometers in length. Each elementaryfibril is a flexible elongated strand comprised of crystalline regionsof cellulose interspersed with disordered amorphous domains ofcellulose. The crystalline regions are segments of cellulose chains thathave been rigidly stabilized by a strong intersecting network ofhydrogen bonds; the amorphous regions, while still bound by hydrogenbonds, are more flexible. These elementary fibrils (microfibrils) arepacked together in biological systems to form larger units calledmicrofibrillated cellulose, which have diameters ranging from about20-50 nm. In biosystems, the microfibrillated cellulose units areaggregated, linked via hemicellulosic moieties, and embedded in a pectinmatrix to form the visible cellulose fibers found in plant cell walls.

The structures of elementary cellulose fibrils and microfibrillatedcellulose permit two discrete cellulose morphologies to be extractedfrom the plant-derived cellulosic raw materials. Crystalline cellulosecan be extracted in particulate form, yielding products that are termedcellulose nanocrystals or cellulose microcrystals, depending on the sizeof the particles. Cellulose can also be extracted as fibers, yieldingproducts that are termed cellulose nanofibers or cellulose microfibers,depending on the size of the fibers. Cellulose crystals and cellulosemicro/nano fibers are extracted by different techniques, yieldingdifferent morphologies with different properties. The two fibrousmaterials, cellulose nanofibers and cellulose microfibers, are extractedfrom plant matter by different techniques from each other, so that theirmorphologies and properties are different. Cellulose nanofibers andcellulose microfibers can be distinguished from each other based ontheir size and shape: cellulose nanofibers (CNF, also known as“nanofibrillated cellulose” or “NFCs”) are much smaller in diameter thancellulose microfibers (CMF, also known as “microfibrillated cellulose”or “MFCs”) and can be straight and rod-like, while CMF are larger indiameter, more flexible in appearance and can be irregular in shape.While the literature cites a range of dimensions for CNF and for CMF,CNF fibers are nanoscale (for example, having a diameter between 4-20nm), while CMF can be much larger still: CMF fibers typically still havediameters in the nano-range, for example 20-100 nm or larger.

In more detail, CMF fibers are produced by mechanical treatment ofcellulosic feedstock, with or without chemical or enzymaticpre-treatment. CMF fibers are elongated with a high aspect ratio,containing crystalline and amorphous regions like native cellulose, andcapable of forming a three-dimensional network. The size distribution ofCMF fibers in a fiber population is wide, with smaller, nanoscale fibersinterspersed in the CMF network with larger fibers. By contrast, for CNFfibers, different processing methods are involved to produce populationsof individual fibrils with a narrow size distribution within thepopulation. The dimensions in the CNF material are more consistentlynanoscale, as compared to CMF fiber populations. As used herein, allthree species (crystalline cellulose, CNF, and CMF) shall be included inthe umbrella term “nanocelluloses” or nanocellulose elements (NCEs).

Nanocellulose (NC) materials hold immense promise for commercialapplications, thanks to their biodegradable nature, low density,abundant source materials, and high mechanical performance. However,although the nano-size geometry and hydrophilic nature of thesecellulosic materials offer opportunities, these features also presentchallenges. A number of applications have been developed that exploitNC's geometry and hydrophilicity. As an example, certain nanocellulosescan be dry blended with inorganic powders, including plaster and cement,to deliver mechanical fortification to structures upon hydration andcuring. However, because they are hydrophilic, NC materials requiremodification so that they can be used in hydrophobic environments. Evenin hydrophilic environments, or within a composite that uses the NC as ahydrophilic component, satisfactory NC dispersion can be difficult,limiting the usefulness of NC elements in many applications.Furthermore, limitations imposed by NC drying and dispersion techniqueslimit the usefulness of these materials for commercial applications.

NCs are usually produced by a series of mechanical and/or chemicalprocedures performed in an aqueous medium, whereby the aqueoussuspension loosens cellulose's interfibrillar hydrogen bonding tofacilitate delamination, resulting in the formation of NC derivativeshaving more useful degrees of polymerization and crystallinity andhaving higher aspect ratios. Typically, the NC materials are dispersedin the aqueous medium at a low concentration (<5 wt %) because theirhigh water-absorption capacity cause them to form a highly viscoussuspensions even at low solid concentrations, due to the entangling ofthe high-aspect-ratio NC elements.

However, these aqueous suspensions of NCs are difficult to manage andexpensive to transport. Therefore, drying technologies have been devisedto convert the NC suspension into a dry powder form. However, drying theNC suspension using conventional techniques (for example, evaporatingthe water at high temperatures) promotes the formation of aggregates(“aggregation”) due to the interaction of hydroxyl groups on the surfaceof the cellulose molecules, and the formation of hydrogen bonds. Thisaggregation process resulting from conventional drying, also calledhornification, is characterized by irreversible or only partiallyreversible bonding between the hydroxyl groups on the NC particles orfibers.

Despite a decade-long series of academic and industrial efforts, successin low-cost and effective drying and redispersion has eluded NCproducers. The twin challenges of (a) NC drying from the aqueous mediain which the NC is suspended and (b) redispersion of the dried NC iscaused by two factors: (1) the propensity of cellulose polymers to formhydrogen bonds with one another, adhering adjacent cellulosic elementsinto irreversible aggregates (i.e., an assemblage of particles durablyattached to each other, resisting redispersion in a suspension); and (2)the huge surface area (per unit weight) associated with the size andmorphology of the NCE, greatly exacerbating adhesion due to hydrogenbonding. If an aqueous slurry of NC is dried in a standard oven, arigid, intimately entangled, brick-like mass is formed on the bottom ofthe drying vessel. This tight network of aggregated cellulosic elementscannot be easily scraped off the vessel, let alone be redispersed inwater, even with intense mechanical agitation. Instead, attempts atredispersion result in large clumps of NC aggregates remaining in theredispersion medium even after hours of stirring. This resistance toredispersion prevents the use of the dried NC material in compositeproducts (cement, concrete, paver, artificial stone, ceramic, plaster,mortar, joint compounds, and the like) in which a dry blend of the NCstrengthening additive must be uniformly distributed throughout thecomposite.

This tendency towards aggregation and hornification and the subsequentresistance to redispersion has eluded a cost-efficient solution, thusforeclosing opportunities for using NC materials in a wide range ofattractive applications. While various drying techniques, e.g., freezedrying, spray drying, supercritical fluid drying and atomization, havebeen investigated by researchers, they have at best yielded smallsamples of redispersed NC elements, using processes whose high cost,energy requirements, and need for specialized equipment preclude theirwidespread adoption.

There remains a need in the art, therefore, for commercial-scale dryingtechniques for NC materials that avoid the aggregation and hornificationproblems, so that solid masses of NC can be produced for laterredispersion. There remains a further need in the art for suchtechniques that are suitable for commercial implementation, at low cost,without excessive energy requirements, and without need for specializedequipment.

SUMMARY OF THE INVENTION

Disclosed herein, in embodiments, are liquid formulations comprising asuspension of nanocellulose (NC) elements and a drying/dispersaladditive, wherein the drying/dispersal additive is selected from thegroup consisting of temperature-responsive polymers, small moleculeadditives in volatile systems, and blocking agents. In embodiments, thenanocellulose elements are derived from lignocellulosic materials, whichcan comprise virgin biomass, and wherein the virgin biomass comprisesspecialty-purpose crops; in other embodiments, the lignocellulosicmaterials comprise waste materials. In embodiments, the NC elementscomprise or consist essentially of crystalline cellulose, or cellulosenanofibers. In embodiments, the drying/dispersal additive is atemperature-responsive polymer, which can be a lower critical solutiontemperature (LCST) polymer or a short-chain oligomer derived from a LCSTpolymer. The LCST polymer can be selected from the group consisting ofmethyl cellulose, hydroxylethyl cellulose, hydroxypropyl cellulose,hydroxypropylmethyl cellulose, ethylhydroxyethyl cellulose,polyvinylcaprolactam, poly(methyl vinyl ether),poly(N-isopropylacrylamide), poly(N,N-diethylacrylamide), poly(ethyleneoxide) and poly(propylene oxide) block copolymer, and elastinpoly(pentapeptide). In embodiments, the drying/dispersal additive is asmall molecule additive in a volatile system, which can be non-ionic orcationic, and which can be biodegradable. The small molecule additivecan be selected from the group consisting of tri(propylene glycol) butylether, di(propylene glycol) propyl ether, propylene glycol butyl ether,propylene glycol propyl ether, ethylene glycol monobutyl ether,propylene glycol monomethyl ether acetate, propylene glycol diacetate,ethylene glycol diacetate, benzyl alcohol, 1-heptanol, and 1-hexanol.The small molecule additive can be selected from the group consisting ofethylene diamine, diethylene triamine, tetraethylene pentaamine,1,3-pentane diamine, piperazine, 1,2-cyclohexane diamine, aniline,pyridine, and piperazine. In embodiments, the drying/dispersal additiveis a blocking agent. The blocking agent can be a non-volatile chemicaladditive, which can be a purine or a pyrimidine. In embodiments, thenon-volatile chemical additive is a purine, and the purine is a xanthineor a xanthine derivative. In embodiments, the blocking agent is ahumectant, which can be selected from the group consisting of glycerin,caprylyl glycol, ethylhexylglycerin, tribehenin, hydrolyzed soy protein,propylene glycol, methyl gluceth-20, phenyl trimethicone, hyaluronicacid, sorbitol and gelatin. In embodiments, the blocking agent can be afatty acid. In embodiments, the blocking agent comprises nanoscaleparticles. In embodiments, the liquid formulation can further comprisean adjuvant.

Also disclosed herein, in embodiments, are methods of processingcellulosic feedstock to form a redispersible, dried NC-containingmaterial comprising NC elements, comprising mechanically defibrillatingthe cellulosic feedstock, thereby forming an initial nanocellulosesuspension comprising the NC elements; treating the cellulosic feedstockwith a drying/dispersal additive before or after the step ofmechanically defibrillating the cellulosic feedstock to form a treatednanocellulose suspension comprising NC elements; and drying the treatednanocellulose suspension to form the redispersible, dried NC materialcomprising NC elements. The methods can further comprise a step ofchemically pretreating the cellulosic feedstock either before or afterthe step of mechanically defibrillating the cellulosic feedstock, andthe step of chemical pretreating can be performed using a pretreatmentagent selected from the group consisting of enzymes, alkaline solutions,acid solutions, ionic liquids, short-chain amines, and positiveoligomeric species. In embodiments, the pretreatment agent is selectedfrom the group consisting of ethylenediamine, o-phenylenediamine,diethylenetriamine, tetraethylenepentamine, 1,3-diaminopentane,ethanolamine, triethynolamine, melamine, and EDTA. In embodiments, themethods further comprise a step of treating the cellulosic feedstockwith a chelating agent before or after the step of mechanicallydefibrillating the cellulosic feedstock. In embodiments, the methodsfurther comprise adding a second drying/dispersal additive to thecellulosic feedstock before, after, or simultaneously with the step oftreating the cellulosic feedstock with the drying/dispersal additive.

In addition, a dried NC-containing material is disclosed herein that isproduced by the methods described above. Further disclosed herein aremethods of producing a formulation comprising suspended NC elements in afluid medium, comprising providing the fluid medium, adding theredispersible, dried NC material described above to the fluid medium,and mixing the redispersible, dried NC material in the fluid medium,thereby suspending the NC elements in the fluid medium. In embodiments,the fluid medium is an aqueous fluid. Also disclosed herein areformulations comprising NC elements redispersed in a fluid mediumproduced by the methods described above.

Disclosed herein, in embodiments, are methods of producing aredispersible, dried NC-containing material with nanocellulose elementsembedded therein, comprising providing the liquid formulation describedherein, wherein the liquid formulation comprises nanocellulose elementsand wherein the liquid formulation comprises a drying/dispersaladditive; and drying the liquid formulation to form a driedNC-containing material with nanocellulose elements embedded within,wherein the redispersibility of the dried NC-containing material isgreater than that of a dried control material prepared by drying acontrol suspension of nanocellulose elements in a liquid medium, whereinthe control suspension lacks a drying/dispersal additive. The method canfurther comprise adding a pretreatment agent to the liquid formulationbefore the step of drying the liquid formulation; the pretreatment agentcan be added before or simultaneous with addition of thedrying/dispersal additive. In embodiments, the pretreatment agent is achemical pretreatment, which can be selected from the group consistingof ethylene diamine, o-phenylenediamine, diethylenetriamine,tetraethylenepentamine, 1,3-diaminopentane, ethanolamine,triethynolamine, melamine, and EDTA. The chemical pretreatment can be achelating agent. Further disclosed is a redispersible, dried,NC-containing material with nanocellulose elements embedded therein thatis produced by the methods disclosed above. In embodiments, thenanocellulose elements are formed as a matrix, which can be a supportfor or a container for an active agent. Advantageously, the matrix canact as a container, and the container can be foamed. In embodiments, thematrix can be shaped as a formed article. In other embodiments, thematrix can be formed as a film, and the film can envelope the activeagent. In embodiments, the formed article is adapted for disruption by aphysical, chemical, or biological mechanism, wherein the disruptionpermits release of the active agent. In embodiments, the formed articlecomprises a first matrix acting as a support for the active agent,wherein the first matrix is formed as a sheet. In other embodiments, theformed article comprises a first matrix formed as a sheet and a secondmatrix formed as a sheet, with the active agent disposed between thefirst matrix and the second matrix, and the active agent can be enclosedbetween the first matrix and the second matrix. In embodiments, theactive agent is selected from the group consisting of laundry products,soaps, detergents, surfactants, bleaches, enzymes, hair hold products,pigments, coloring agents, odor-related agents, emollients, cosmetics,pharmaceutical products, medical products, and agricultural activeingredients. In embodiments, the matrix further comprises fillerparticles, which can act as pore closure materials. In embodiments, thematrix has abrasive properties. In embodiments, the NC-containingmaterial further comprises a barrier-producing material, which can bedeployed as a coating on an upper or lower aspect (e.g., on the top orbottom) of the matrix, or which can be mixed into the matrix. Inembodiments, the barrier producing material imparts oil and greaseresistant properties to the NC-containing material, or imparts waterresistant or water-vapor resistant properties to the NC-containingmaterial. In embodiments, the barrier-producing material comprises abiopolymer.

Also disclosed herein, in embodiments, are methods of redispersingnanocellulose elements, comprising providing the redispersible, dried,NC-containing material described above, and adding a redispersing fluidto the dried NC-containing material, thereby redispersing the NCEsembedded in the redispersible, dried NC-containing material. Theredispersing fluid can be an aqueous fluid. Further disclosed herein areredispersed NC-containing formulation comprising NC elements suspendedin a redispersing fluid, wherein the redispersed NC formulation has beenproduced by the methods described above. In embodiments, the formulationcan be foamed. In embodiments, the formulation further comprises anactive agent attached to the NC elements or embedded in a matrix formedfrom the NC elements. In embodiments, the active agent can be askin-treating substance, or a pharmaceutical or nutraceutical product,or a cosmetic product, or an odor-related active agent, or anagricultural active ingredient. Also described herein are methods ofmanufacturing a formed article, comprising drying the formulationdescribed above into a selected shape, wherein the selected shape whendried produces the formed article. In addition, methods are disclosedherein for treating a surface, comprising applying the formulationdescribed above to the surface and allowing the formulation to dry. Inembodiments, the surface is a hair shaft or a skin surface. Inembodiments, methods are disclosed herein for treating a skin disorderor skin condition, comprising applying the formulation described aboveto a selected area of skin in need of treatment. Methods are alsodisclosed herein for treating an agricultural product, comprisingapplying the formulation described above to the agricultural product.

Further disclosed herein, in embodiments, are methods of producing acomposite matrix, comprising providing an existing matrix composition,and incorporating a population of additive NCEs into the existingmatrix. The existing matrix composition can comprise or consistessentially of organic materials, which can be pulp or pulp-basedmaterial. In embodiments, the existing matrix composition is coated withor impregnated with the additive NCEs. Also disclosed herein arecomposite materials prepared by the foregoing methods. In embodiments,the existing matrix is a hydrophobic matrix, and the additive NCEs havebeen hydrophobized for use in the hydrophobic matrix. In embodiments,the existing matrix comprises a biodegradable polymer, which can be anatural polymeric material. In embodiments, at least a portion of theadditive NCEs act as fillers or act as pore-closers in the existingmatrix. In embodiments, the composite material further comprises asecondary additive, which can be a plasticizer or a hydrophobiccellulose additive. In embodiments, the composite material exhibits aspecialized property, which can be is selected from the group consistingof a mechanical property, a barrier property, and an adscititiousproperty. In embodiments, the specialized property is a mechanicalproperty, which can be a reinforcement of a mechanical characteristic ofthe existing matrix. In embodiments, the specialized property is abarrier property, which can be an oleophobic barrier property, ahydrophobic barrier property, or both. In embodiments, the specializedproperty is an adscititious property, which can be a conductiveproperty. In such embodiments, the population of additive NCEs caninclude a subpopulation of NCEs having conductive properties, and theconductive properties of the subpopulation can be produced in thesubpopulation via the silver mirror reaction. In embodiments, thecomposite material can be a foamed article, which can comprise cellulosemicrofibers within the population of additive NCEs; in embodiments, thefoamed article can comprise a barrier-producing material. Furtherdisclosed herein are articles of manufacture comprising the compositematerials disclosed above. In embodiments, the article of manufacture isselected from the group consisting of recreational equipment articles,athletic shoes, architectural paint products, construction materials,durable inks, and 3D printing materials. In embodiments, the article ofmanufacture can comprise the composite material disclosed above, whereinthe composite material exhibits a specialized property. Such articles ofmanufacture can be formed as drinking straws, films, sheets, or fibersor non-woven fabrics; such fibers or non-woven fabrics can exhibitoptimized properties, and they can be formed into an artificial leather.

DETAILED DESCRIPTION OF THE INVENTION 1. Constituents for RedispersibleNanocellular Materials

It is understood that NC materials suitable for treatment with thesystems and methods disclosed herein can be derived from all types ofcellulosic raw materials, in particular plant-derived cellulosic rawmaterials, which can also be termed lignocellulosic materials.Lignocellulosic materials are formed of cellulose polymers as describedabove bound with varying amounts of lignin. Lignocellulosic materialscan include virgin biomass, as is found naturally occurring plants liketrees, bushes, and grass. Lignocellulosic materials can include wastematerials from consumption or from industries such as agriculture (e.g.,corn stover and corncobs, sugarcane bagasse, straw, oil palm empty fruitbunch, pineapple leaf, apple stem, coir fiber, mulberry bark, ricehulls, bean hulls, soybean hulls (or “soyhulls”), cotton linters, blueagave waste, North African glass, banana pseudo stem residue, groundnutshells, pistachio nut shells, grape pomace, shea nut shell, passionfruit peels, fique fiber waste, sago seed shells, kelp waste, juncusplant stems, and the like), or forestry (saw mill and paper milldiscards). Lignocellulosic materials can include specialty-purpose cropssuch as switchgrass and elephant grass cultivated for uses such asbiofuels, capable of multiple harvests. Plants having use aslignocellulosic materials can be woody (such as trees, with firm stems,and with multiyear growth cycles) or non-woody, having weak stems andannual or limited multiyear growth cycles. Non-woody plants areparticularly advantageous, typically possessing low amounts of ligninrelative to the amount of cellulose they contain. As would be understoodby those of skill in the art, different techniques are available forprocessing the various lignocellulosic materials to extract NC materialstherefrom.

Disclosed herein, in embodiments, are additives that can be used forinhibiting or disrupting the hydrogen bonding of NC materials atelevated temperatures (for example, during drying), while retaining highintrinsic hydrophilicity, thus allowing facile redispersion in aqueousmedia. The formulations and methods disclosed herein include severaldifferent categories of additives (termed “drying/dispersal additives”):(1) certain temperature-responsive polymers that can introduce spacingbetween NC particles or fibers (collectively, “NC elements”) duringdrying, thus preventing their clumping; (2) certain volatile smallmolecules that can create space between NC elements during drying; and(3) certain nonvolatile small or large molecules that hinder hydrogenbonding between or among NC elements during drying. All of thesematerials act to disrupt hydrogen bonding at elevated temperatures orunder other circumstances, while creating gaps between or among the NCelements with further drying that will permit subsequent redispersion.

As used herein, the term “drying” for an initial suspension of NCelements (termed the “initial NC suspension,” understood to be thesuspension containing the NC elements that is initially produced duringthe defibrillation processes, as exemplified in the description thatfollows) refers to the application of heat and/or any other dewateringtechnology to the initial NC suspension that results in a decrease inthe water content of the initial NC suspension so that the initial NCsuspension is converted to a solid or semi-solid material comprising theNC elements that were present in the initial NC suspension. This driedsolid or semi-solid material can be referred to as the “dried NCmaterial.” As used herein, the term “redispersion” refers to a processby which the dried NC material is suspended in a fluid medium (whetheraqueous or non-aqueous) so that there is a substantially completedissolution of the dried NC material (whether semi-solid or solid) intoits component NC elements. In embodiments, aqueous resuspending fluidscan be used; in other embodiments, non-aqueous resuspending fluids canbe used, such as fluids having hydrophobic properties or amphiphilicproperties. In embodiments, redispersion results in a suspension of theNC elements so that they are formed as individual NC elements orcoalescences of individual NC elements (either, referred to herein as a“resuspended particles”) wherein such resuspended particles have anaspect ratio of greater than 10. In embodiments, the resuspendedparticles have an aspect ratio between about 10 and about 300, orbetween about 10 and about 200. In embodiments, the resuspendedparticles have an aspect ratio between about 50 and about 150. Inembodiments, the resuspended particles have an aspect ratio betweenabout 25 and about 75. In other embodiments, the resuspended particleshave an aspect ratio between about 75 and about 125.

While certain additives (for example, certain LCST polymers, asdescribed below) are suitable for use as single agents for facilitatingdrying and redispersion, other additives lend themselves for use asadjuvants in combination with a main drying/dispersal additive, eitheradministered into the initial NC suspension simultaneously with the mainadditive, or as pre-treatment to the initial NC suspension or anyprecursor thereof before adding the main additive, or as apost-treatment to the initial NC suspension following the addition ofthe main drying/dispersal additive. Drying/dispersal additives comprise,without limitation, temperature-responsive polymers, small moleculeadditives in volatile systems, and blocking agents. Maindrying/dispersal additives and adjuvant additives that are used incombination with a source of NC elements to produce the liquidformulations and derivative redispersible dried materials of the presentinvention are termed, collectively, “primary additives.”

a. Temperature-Responsive Polymers

In embodiments, certain temperature-responsive polymers can be employedto create space between the NC elements during drying, therebypreventing the NC elements from aggregating during the drying process.Temperature-responsive polymers especially suitable for this purpose arethose that exhibit a phenomenon known as LCST (lower critical solutiontemperature) phase behavior. It is understood that certain LCST polymersare hydrophilic below their LCST transition temperature and becomereversibly hydrophobic above their LCST transition temperatures. Inother words, below the LCST point, the polymer shows high affinitytowards water, consistent with its intrinsic molecular hydrophilicity.However, above the LCST point, the polymer repels water and shunshydrogen bonding. This is evidenced by the observed thermogelation ofpolymer solutions above this transition temperature. As the polymeric oroligomeric LCST additive self-assembles on the surface of the NCelements (in the form of mono-layer or a few molecular layers), dryingof NC elements are affected so that their ultimate redispersion isfacilitated.

In more detail, the LCST polymer can be added to the initial NCsuspension at a temperature below the LCST polymer's transitiontemperature. As water evaporates from the initial NC suspension duringdrying, its temperature rises and approaches the boiling point of water,coming to exceed the LCST polymer's transition temperature, at whichpoint the LCST polymer loses its hydrophilic character and becomeshydrophobic. When it becomes hydrophobic, the LCST polymer interfereswith the hydrogen bonds that are forming between the NC elements. Thehydrophobic nature of the LCST polymer now dictates aggregation ordisaggregation of the NC elements, instead of these processes beingdriven by the interaction of the cellulosic units of the NC elements.

In embodiments, selected LCST polymers can markedly or completely hinderthe dense aggregation of NC elements upon drying. In embodiments, theability of selected LCST polymers to disrupt aggregation of NC elementsis independent of equipment selection and manner of drying. For example,the suspension containing the LCST polymer and the NC elements can beleft quiescent during drying. A wide range of drying temperatures andpressures can be applied to the initial NC suspension in the presence ofselected LCST polymers to accomplish aggregate-free drying. Dried NCmaterials produced using selected LCST polymers as described herein canbe readily redispersed in water with gentle agitation or stirring, withminimal or no clotting or residual aggregations identified in theredispersed suspension. These features give rise to wide latitude inprocessing parameters.

In embodiments, the list below offers examples of LCST polymers andtheir analog short-chain oligomers that can be used to preventaggregation and facilitate redispersion of NC elements.

-   -   Methyl cellulose    -   Hydroxylethyl cellulose    -   Hydroxypropyl cellulose    -   Hydroxypropylmethyl cellulose    -   Ethylhydroxyethyl cellulose    -   Polyvinylcaprolactam    -   Poly(methyl vinyl ether)    -   Poly(N-isopropylacrylamide)    -   Poly(N,N-diethylacrylamide)    -   Block copolymer of poly(ethylene oxide) and poly(propylene        oxide)    -   Poly(pentapeptide) of elastin

Note that thermo-gelation temperature of the cellulose derivativeslisted above depends on the type and degree of substitution and istunable by structural design. Advantageously, a selected LCST polymerfor use as a drying/dispersion additive can have a transitiontemperature that is greater than the ambient temperature (forexample, >25° C.), so that the polymer remains in solution until thedrying step commences.

b. Volatile Small-Molecule Additive Systems

In embodiments, volatile systems comprising small molecule additives canbe employed to create space between the NC elements during drying toprevent the NC elements from aggregating during the drying process,either alone or in combination with other additives. The selected smallmolecule additives for use with volatile systems are miscible with waterand have a boiling point higher than that of the co-existing water. Thesmall molecule additive useful in a volatile system is furthercharacterized by its greatly lower hydrogen-bonding tendency compared towater. As the additive-loaded volatile system containing the NC and theselected small molecules undergoes drying, water molecules evaporatepreferentially, leaving the small molecule additive behind due to itshigher boiling point and thereby increasing the concentration of theadditive in the solution that remains between adjacent NC elements. Inembodiments, the molecular segments of the volatile small moleculeadditives comprise both polar and non-polar functionalities. Not beingbound by theory, it is envisioned that the polar segments are attractedby the cellulosic hydroxy groups while the non-polar segmentssimultaneously interfere with hydroxy-hydroxy interactions, thusreducing adherence between and among the NC elements. Then, as thetemperature in the system rises, the additive evaporates, leaving behindthe NC elements surrounded by air. The resulting dried material,containing NC elements that are separated from each other by air, can bereadily re-dispersed without the formation of observable clumps/clots orconcentration variations. The redispersed suspension comprisesresuspended NC particles that are uniform in distribution within thesuspension, wherein the NC elements retain their nano-sizecharacteristics and can achieve redispersion with only very mildagitation/stirring.

In embodiments, the lists below offer examples of small moleculeadditives that can be used in the aforesaid volatile systems to preventaggregation and facilitate redispersion of NC elements. Exemplaryadditives can be divided into two categories: non-ionic and cationiccompounds.

Non-ionic candidates can include, without limitation:

-   -   Tri(propylene glycol) butyl ether (TPnB)    -   Di(propylene glycol) propyl ether (DPnP)    -   Propylene glycol butyl ether (PnB)    -   Propylene glycol propyl ether (PnP)    -   Ethylene glycol monobutyl ether    -   Propylene glycol monomethyl ether acetate    -   Propylene glycol diacetate    -   Ethylene glycol diacetate    -   Benzyl alcohol    -   1-Heptanol    -   1-Hexanol

Cationic candidates can include, without limitation:

-   -   Ethylene diamine    -   Diethylene triamine    -   Tetraethylene pentaamine    -   1,3-Pentane diamine    -   Piperazine    -   1,2-Cyclohexane diamine    -   Aniline    -   Pyridine    -   Piperazine

In embodiments, the small molecule additives can evaporate completelyfrom the initial NC suspension, just leaving behind the NC elementswithout additive residue. However, in other embodiments, trace amountsof the small molecule additives can remain. For example, with certaincationic additives, their cationic groups can adhere to cellulosemolecules, so that trace amounts of the additive remain adherent to thecellulose after complete drying. For most industrial applications, thetrace residues of these additives do not pose a health or environmentalproblem. However, in embodiments, a biodegradable cationic smallmolecule such as 1,3-pentane diamine is advantageous.

c. Blocking Agents

In embodiments, non-volatile small or large molecule additives can beemployed themselves, apart from volatile systems as described above, tohinder hydrogen bonding and/or to create space between the NC elementsduring drying, thereby blocking interactions between the NC elements andthus preventing the NC elements from aggregating during the dryingprocess. In embodiments, surface functionalized nanoscale particles canbe employed in the same manner. Such non-volatile small or largemolecule additives and nanoscale particles carrying out this blockingfunction are referred to herein as blocking agents or blockers As usedherein, the term “blocking agent” or “blocker” includes any non-volatilechemical additive or nanoscale particulate material that itself hindershydrogen bonding or creates spaces among NC elements, whether thesubstance is interposed between or among NC elements, or whether thesubstance offers temporary competitive binding sites for the NCelements, or otherwise. As an example, caffeine and other xanthinederivatives are small-molecule blockers that can be used advantageouslyto facilitate isolation and re-dispersion of NC elements. Not beingbound by theory, it is envisioned that the aromatic nitrogen atoms incertain purines (such as caffeine and other xanthines or xanthinederivatives) and pyrimidines can become hydrogen-bonded with the hydroxygroups of the cellulose, presenting a flat, relatively non-polar, andmolecularly-lubricating and water-screening outer surface, thushindering adhesion between and among NC elements. Advantageously,caffeine, and other xanthines and xanthine derivatives can typically beused in quantities that do not present health or environmental problemseven when used in sufficient dosages to facilitate NC dispersion.

As another example, certain humectant substances can be employed asblocker molecules. Humectants possess multiple hydrophilic sites(hydroxyls, esters, and ammonium groups) that can form hydrogen bondswith the surface of the NC elements, thus screening the interaction ofthese elements with each other via hydrogen bonding, and therebyimpairing aggregation. Moreover, these hygroscopic substances arebiocompatible and are already widely used in the pharmaceutical,cosmetic, and food industries. Exemplary short and long humectantcandidates include but are not limited to: glycerin, caprylyl glycol,ethylhexylglycerin, tribehenin, hydrolyzed soy protein, propyleneglycol, methyl gluceth-20, phenyl trimethicone, hyaluronic acid,sorbitol and gelatin.

As another example, fatty acids can be employed as blockers as well.Fatty acids contain hydrophilic sites and a hydrophobic tail. Thehydrophilic site can form hydrogen bonds with the surface of NCelements, thus screening the interaction of these elements with eachother via hydrogen bonding, and thereby impairing aggregation.Advantageously, fatty acids can be selected that do not contain so manyhydrophilic sites that much hydrogen bonding will occur between fibersand the blockers. In embodiments wherein too many hydrogen sites maycause aggregation, the hydrophobic tail of the fatty acid blockers canact to physically prevent aggregation of NC elements by preventing orinterfering with hydrogen bonding. In embodiments, the blocking agentcan be a fatty acid, such as stearic acid, palmitic acid, myristic acid,lauric acid, capric acid, caprylic acid, caproic acid, and the like. Fordispersion purposes, a water-soluble fatty acid may be preferable.

2. Additional Processing Options

It is understood that the drying/dispersal additives disclosed hereincan be introduced into a NC-containing suspension individually or incombination to improve the drying process for the NC and to facilitateits redispersion. Drying/dispersal additives can also be used incombination with other agents that enhance their efficacy, even if thoseother agents are not effective as drying/dispersal additives when usedalone; such agents, used in combination with the drying/dispersaladditives to enhance their efficacy, are termed “adjuvants.” It isfurther understood that one or more of the drying/dispersal additives oradjuvants can act together in a synergistic manner. Moreover,combinations of the drying/dispersal additives can be introducedsequentially during the preparation of the initial NC suspension, and/orbefore, after, or during the processes that are employed to produce theinitial NC suspension from a feedstock of cellulosic sources, with orwithout the addition of adjuvants. For example, non-polymeric additivescan be added during the processes that are employed to produce theinitial NC suspension from feedstock, but desirably are to be addedafter chemical pretreatment.

Processes for forming NC-containing suspensions (i.e., initial NCsuspensions) suitable for treatment using the formulations and methodsdisclosed herein are familiar in the art. To form such a NC-containingsuspension, cellulose sources can be processed using mechanicaltechniques and optional chemical treatments to extract the componentcellulose nanomaterials and retain them as suspended in a liquid medium.The NC elements thus extracted form the initial NC suspension, which canbe treated using the disclosed formulations and methods.

In more detail, mechanical treatments such as high-pressurehomogenization, microfluidization, super-grinding, cryo-crushing, steamexplosion, refining, and high-intensity ultrasonication are known in theart for disintegrating the cellulose source materials to yield theircomponent NC elements; other mechanical techniques will be familiar toartisans in the field having ordinary skill. Such mechanical treatmentscan be termed forms of mechanical defibrillation. Mechanical treatments,however, require considerable amounts of energy. Therefore, in order toreduce energy consumption during the mechanical defibrillationprocesses, a variety of chemical and enzymatic strategies have beenemployed to pretreat the cellulose sources before their mechanicalprocessing, such strategies being collectively termed “chemicalpre-treatments” herein. In addition, chemical modification of the NCelements can be performed after mechanical defibrillation to alter theirproperties.

Drying/dispersal additives as disclosed herein can be used in thevarious suspensions of partially treated cellulose sources, instead ofor in addition to being used to treat the primary NC suspensionresulting from the extraction of the NC elements from the cellulosesource feedstock. In exemplary embodiments, a single drying/dispersaladditive can be used to treat a feedstock suspension of partiallytreated cellulose sources, for example a suspension of cellulose sourcesthat has been pretreated chemically but have not yet been subjected tomechanical defibrillation. For example, a volatile additive can be usedin this way. Volatile additives are typically formulated as non-viscousfluids that can be injected directly into the pulp feedstock suspension,for example after its chemical pretreatment and/or immediately before itundergoes mechanical defibrillation process (homogenizing,microfluidization, grinding, high intensity ultrasonication, and thelike). In this manner, volatile moieties are intermingled between andamong individual fibers as they detach from larger pulp (cellulose)strands, an architecture that is retained during mechanicaldefibrillation.

In another embodiment, a non-volatile additive or atemperature-responsive polymer such as a LCST polymer can be used totreat the partially-treated cellulose feedstock instead of or inaddition to using a drying/dispersal additive to treat the initial NCsuspension. Non-volatile additives, as well as LCST polymers, generallycome as viscous fluids or powdered solids to be dissolved aqueoussolutions. Due to their high viscosity, these components are desirablyadded after mechanical defibrillation, either by directapplication/dissolution or by combining a concentrated solution of theadditive with the NC suspension effluent.

In other embodiments, pretreatments with various pretreatment agents maybe useful prior to adding the drying/dispersal formulations disclosedherein. For example, cellulose sources can be subjected to certainchemical pretreatments before mechanical defibrillation, as mentionedabove. Chemical pretreatments such as enzymes, alkaline-acid solutions,and/or ionic liquids, for example, can break down lignin andhemicellulose in cellulose sources, while preserving cellulose moieties.These chemical pretreatments help reduce the energy consumption ofsubsequent mechanical processing, as described previously. Furthermore,chemical pretreatments can render the surface chemistry of the extractedNC elements more receptive to treatment with the drying/dispersaladditives disclosed herein. It is known that the surface chemistry of NCelements varies, depending on both the raw source of the cellulosicmaterial (e.g., softwood, hardwood, soy hulls, wheat straw, bagasse,sugar beet pulp, and the like) and the processing technique implemented(e.g., Kraft vs Sunburst). Moreover, additional chemical treatments suchas carboxymethylation, oxidation, and sulfonation can be implementedduring industrial processes to create permanent anionic charges on theNC surfaces. To optimize the surface chemistry of a population of NCelements for treatment with the drying/dispersal additives disclosedabove, these elements can be pretreated with short amines or positiveoligomeric species to mitigate ionic forces between the NC elements;such pretreatment can be carried out before or in conjunction withadding the drying/dispersal additives. Examples of such pre-treatmentagents include: ethylene diamine, o-phenylenediamine,diethylenetriamine, tetraethylenepentamine, 1,3-diaminopentane,ethanolamine, triethynolamine, melamine, and EDTA; other pre-treatmentagents will be familiar to those having ordinary skill in the art.

In certain embodiments, chelating agents such as EDTA or comparablechelating agents such as MGDA (methylglycinediacetic acid trisodiumsalt), GLDA (tetrasodium glutamate diacetate), GEDTA (EGTA) (ethyleneglycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid), and thelike, are useful as pre-treatments if a hard water source is employed tosuspend the NC elements. In an embodiment, a LCST polymer can beselected as a drying/dispersal additive, to be used in a NC suspensionafter using or simultaneous with using EDTA to chelate the hard watercations. In embodiments, a chelating agent such as EDTA can be used totreat the initial NC suspension, thereby complexing divalent cationsresident in the suspending fluid.

Other useful pre-treatments can be readily envisioned by those havingordinary skill in the art.

3. Exemplary Articles of Manufacture

In embodiments, nanocellulose elements (NCEs) prepared in accordancewith the systems and methods disclosed herein can be incorporated into awide range of articles of manufacture. NCEs offer significant advantagesfor forming commercial products.

In embodiments, these materials can be engineered to provide a matrixthat supports other active agents in formulations or compositions; suchmaterials advantageously provide vehicles having properties such asoptical transparence and mechanical strength for carrying and deliveringthe active agents conveniently for their intended use. As used herein,the term “active agent” refers to any substance that produces a desiredchemical, physical, or biological effect, wherein the substance iscapable of producing a chemical, physical, or biological effectindependent of its association with the NCE products (matrices,coatings, substances, fillers, etc.) as disclosed herein. Such activeagents can be contained in (e.g., transported within, enveloped by,dispensed from, or otherwise directed to a designated site of activityby) the NCE-based products disclosed herein. As examples withoutlimitation, active agents can include laundry products (e.g., substancessuch as laundry detergents, bleaches, enzymes, and fabric softeners),soaps, cosmetics, pharmaceutical products, agricultural activeingredients, and the like (certain of which are described in more detailbelow); such active agents can be supported by a NCE matrix, embedded init, attached to it, or otherwise associated with it, wherein the matrixpermits the active agent to be delivered to the site of activity for theactive agent. In certain embodiments, a NCE-based matrix can support theinclusion of active agents having their own properties but that areintended to modify the intrinsic properties of the matrix itself, suchas pigments, dyes or other colorizing agents to add or change color,fragrances, odor absorbers, disinfectants, and the like; such activeagents can thereby become incorporated into an article of manufacturecomprising the matrix, to impart their properties to the final formedarticle.

In other embodiments, materials comprising NCEs can be incorporated intonon-NCE matrices to improve the properties of such non-NCE matrices,including, inter alia, improved strength and resiliency. As has beendescribed above, notwithstanding the cheap, abundant, sustainable andbiodegradable features of NCEs, their widespread adoption in articles ofmanufacture has been constrained by the drawbacks associated with thesuspension of these particles: once suspended, NCEs requiretransportation in substantial volumes of liquid; if the suspensiondries, it undergoes irreversible hornification, which prevents the NCEscontained therein from becoming resuspended. The methods andcompositions disclosed herein make NCEs resuspendable, and thusavailable for inclusion in a variety of products, examples of which areset forth in the present disclosure.

a. NCEs as Matrices: General Characteristics

Dispersed NCEs produced as disclosed herein can be formed into highlyporous three-dimensional nanoscale networks capable of holdingfunctional or active agents within their interstices, and capable ofbeing engineered to optimize their own intrinsic properties with orwithout adding other ingredients. Such matrices can be formulated assolids, gels, liquids, and the like, to meet the specific product'sneeds. Moreover, the matrices, once created, can be shaped or moldedinto any convenient geometry, such as chips, strips, balls, cubes,sheets, etc., as required by the product category, to produce articlesof manufacture. Once formed, a NCE matrix can be used as is, or can beredispersed in water or other aqueous redispersion fluids to form thefinal product.

In embodiments, an NCE-based matrix article of manufacture is intendedto envelop, contain, enclose, support, or otherwise deliver activeagents. In embodiments, the NCE-based matrix acts as a carrier for otheractive agents, with the active agents embedded within, attached to, orsupported by the matrix structure; under such circumstances, the matrixcan be termed a support for the active agent. In other embodiments, theNCE-based matrix encloses or envelopes the active agent, and acts as acontainer for the active agent. In either case, the matrix serves toconvey the active agent to a site of its activity, and the matrix isengineered to deliver the active agent to the site of its activity.Articles of manufacture can be constructed comprising NCE-based matricesacting as supports, containers, or both. In embodiments such articles ofmanufacture can be adapted for disruption by physical, chemical, orbiological mechanisms, thereby releasing the active agents they supportor contain. Such articles of manufacture can be engineered to produce,for example, frangible or dissolvable or other properties permittingdisruption (e.g., able to be digested by microorganisms or hydrolyzed byenzymes), so that they are adapted for delivery of the active agentsthey contain, for example upon encounter with mechanical force (e.g.,tearing, squeezing, puncturing, and the like) or upon encounter with achemical solvent such as an aqueous fluid or upon encounter with adestructive biological entity. The encounter of the article ofmanufacture with such physical, chemical, or biological mechanisms canimpair the integrity of the article of manufacture sufficiently topermit it to deliver the active agent it contains or supports into/ontothe area, surface, substance, etc., designated for the activity of theactive agent.

In other embodiments, the structure of the NCE matrix itself providesthe desired properties for the article of manufacture. A NCE matrix canbe shaped to provide the structural and architectural features that aparticular application requires. Under these circumstances, the NCEmatrix produces the desired effects in a product by virtue of itsmechanical or structural properties. In embodiments, the NCE matrix canincorporate secondary additives that impart other advantageousproperties to the matrix itself, apart from the ability of the matrix asa carrier for active agents.

Examples of NCE matrices as carriers for active agents and as structuralunits or components are set forth below, to illustrate the principles ofthe invention.

i. NCE Matrices as Carriers: Product-Dispensing Vehicles

NCE matrices are suitable for use in a variety of product dispensingapplications, and can readily serve as convenient vehicles fordispensing products that are embedded within the matrix. Without beingbound by theory, it is understood that active agents can be introducedinto NCE matrices so that they are infused into and reside within theinterstices, or coat the matrix framework or both. A variety ofadvantageous properties can be imparted to an article manufactured fromNCE matrices, by introducing secondary additives into the matrix thatconvey the desired properties. For example, specialized release papercan be prepared using silicone adhesives within the NCE matrix, so thatless adhesive backing is required.

In embodiments, NCE matrices can serve as vehicles for active agentsused in the household products and personal care industries. Becausethey can be dehydrated and redispersed, NCE compositions prepared inaccordance with the methods disclosed herein can be used as vehicles foractive agents such as detergents, bleaches, fabric softeners, soaps,fragrances, skin care items, cosmetics, and the like.

Once the desired NCE matrix suspension has been formed, including theactive agents and other secondary additives disposed within, it can bedried for use as a formed article. A dried NCE suspension containing thedesired active agents in the NCE interstices can be formed as a dried orgelatinized sheet, a chip, a ball, a cube, etc., that can then berehydrated with resuspension and release of the active agent. These formfactors enable convenient transportation and storage for the formulationwithout requiring a large fluid volume.

For example, a sheet can be formed using an NCE-based matrix to dispenseproducts or active agents in a desired environment over a desired timeperiod. Sheets can be formed from NCE-mased matrices that have detergentand/or other laundry agents (e.g., enzymes or bleach) disposed withinthe matrix interstices; this sheet can be delivered into a washingmachine or dishwasher and allowed to come into contact with water,allowing the laundry agents(s) to be delivered and the NCE-based matrixto be ultimately dissolved with dispersal of the NCE components.

As another example, a redispersible dried chip, plaque, strip, or thelike, can thus support a variety of active agents in a convenient, dryvehicle, allowing them to be released as a finished formulation withsimple rehydration or redispersion. As an example, soap or shampoo chipscan be produced from a NCE suspension containing the desired soapproducts by dehydrating the suspension to produce a solid composition.The lightweight, conveniently sized chip can be rehydrated with water bythe consumer, to form a reconstituted, finished liquid formulation on anas-needed basis. In a commercial embodiment, a manufacturer can produceprecisely measured chips for use with proprietary vessels of knownvolume, allowing the consumer simply to insert the chip and fill thevessel with the designated amount of water. In embodiments, a vessel forreconstituting the NCE-based composition can be reusable, thuspermitting the manufacturer to avoid the use of plastic or glasscontainers for transporting, displaying, and storing household productsor cosmetics. In other embodiments a vessel is not needed, and a chip ofthe NCE-based composition can be held in the hands while washing withwater. Thus, reconstitution happens during the hand-washing process,which can be especially useful for traveling or in areas where water isnot readily available.

While a flattened chip shape has been described as an exemplaryembodiment, it is understood that the NCE-based composition can beformed in any desirable geometry, including but not limited to regularor irregular spheres, rectangles, cubes, cylinders, thick sheets, rolls,and the like, with the shape selected to provide an appealing form forcustomer utilization.

Examples of active agents usable within NCE-based matrices for householduses include bleaches, laundry detergents, and combinations thereof,dishwasher soap and dishwasher treatments, toilet bowl cleaners, andother industrial heavy-duty cleaning products such as oven cleaners,floor cleaners, and the like. These products can be formulated toincorporate other advantageous properties, such as sustained release.Analogous NCE-based products can be envisioned for other fields, such asmedical products in which the active agent can be borne within thematrices of the NCE composition.

In embodiments, active agents such as are exemplified above can beembedded in sheets formed from NCE matrices to be delivered in clothesdryers, as substitutes for the familiar dryer sheets. Conventional dryersheets are fibrous sheets, usually made from compressed polyester orcellulose fibers, that are coated in a thin, waxy layer of laundryproducts like fabric softeners, scents, static reducers, and the like.When used in a hot dryer, these laundry substances melt off the dryersheet fibers and distribute evenly throughout the laundry load, applyingall the benefits of the materials listed. However, the materials used inconventional dryer sheets can be petroleum-derived, and can resistbiodegradation, leading to a buildup of these materials in landfills. Asan alternative, NCEs can be used as the carrier matrix for the laundryproducts, replacing conventional nonwoven materials, providing anenvironmentally friendly, biodegradable alternative to conventionaldryer sheets. In embodiments, NFCs, MFCs, or mixtures thereof can beused alone or in combination with other matrix materials such as pulp orpulp-based materials to make articles like the dryer sheets disclosedherein. Advantageously, use of a NCE matrix provides high strength andbiodegradability, while forming a porous material that can act as acarrier for the active agents to be distributed within the dryer.

To this end, the formulations for NCE redispersion as disclosed hereincan be modified to have higher concentrations of hydrophobic cellulosepolymer (for example, including a hydrophobic cellulose polymer (e.g.,methyl cellulose) in ranges from about 0% to about 10%) to create astrong network of fibers. In embodiments, the plasticizer shouldpreferably be hydrophobic to protect the sheet from being saturated bywater and weakened. Plasticizers such as the diesters and triesters ofcertain acids, like triethyl citrate or diethyl phthalate, and thediesters and triesters of certain alcohols, such as triacetin andvegetable oils, are advantageous. Though the more hydrophobicplasticizers can be difficult to mix into the water-based NCEsuspension, mechanical mixing can overcome these limited solubilities toimpart the desirable hydrophobic properties to the dryer sheets thusformed, so that they stand up to the stresses imposed by the heat andmotion within the clothes dryer. Fatty acids can also be used asplasticizers, especially in more hydrophobic applications.

After the NCE matrix is formed, the materials that typically coat dryersheets can then be applied using techniques familiar in the art, forexample an aerosolized spray that disperses particles of wax thatcontain substances such as fabric softener, antistatic chemicals, andnatural scents suspended therein. This waxy material then hardens on thesurface of the sheet, so that it can melt off the sheet and coat theclothes in the heated dryer. In embodiments, the active agents can bepre-mixed into the NCE matrix before it is dried to form sheets. Inother embodiments, the NCE matrix can be formed, extruded and driedfirst, with the wax containing the active agent(s) applied afterwards.Using the NCE matrix offers a greater available surface area for eachsheet, as compared to conventional laundry sheets of similar dimensions,due to the increased surface area that is innate to much smaller fibers,as well as the larger number of interstices. With the greater surfacearea, each sheet can carry a larger volume of active agents per sheet,reducing the necessary number of sheets needed for a single load oflaundry.

In embodiments, a laundry sheet can be made as a single sheet, using theNCE dispersant technology previously described, for example using acellulosic polymer and a plasticizer to facilitate such dispersibility.As the matrix is formed from the redispersed NCEs, prior to shaping itas a single sheet, appropriate active agents, including laundry productactive agents such as laundry detergents, cleaning products, and/orsurfactants, bleaches, and enzymes, and optional ingredients such aschelating agents, anti-foaming agents, emulsifiers, and the like can beadded. The mixture of redispersed NCEs, active agents and secondaryadditives can then be mixed vigorously; in embodiments, sufficientmixing can be applied so that the mixture is aerated into a foam. Themixture can then be formed into sheets and dried using conventionaltechniques. Once prepared and cooled, the resulting sheets can provide astable base layer that includes within its substance core laundry agentssuch as detergents/surfactants or other cleaning products, but that alsoprovides a platform for supporting other, more active agents such asenzymes and bleaching agents that would not tolerate heat treatment.

In other embodiments, NCE matrices, configured as sheets, can be used toenclose active agents in a layered arrangement. For example, two outerlayers formed from NCE-based sheets can encase a laundry detergent, acleaning product, or other active agent between them like a sandwich.Such active agents s can then be dispersed on the surface of a preparedsheet, which is then covered by another sheet, with the two layerspressed together gently to trap the active agents in a sheet “sandwich”without applying damaging heat or force to these more delicatecomponents. The composite layered structure thus becomes available todispense both the active agents embedded in the matrix during the sheetformation (detergents, surfactants, emulsifiers, chelating agents forhard water treatment, and the like) and any active agents or secondaryadditives dispersed on the surface of the matrix and not subjected toheat or excess pressure. All ingredients become available during thelaundry process when the layered carrier structure is exposed to waterand decomposes, releasing all of the active agents and/or otheradditives it supports.

The active agent can be present in a solid form, for example as apressed powder, or suspended/emulsified in a viscous gel, or otherwise.The NCE layers, being dispersible, can release the active agent asrequired by the specific application, for example when contacted bywater (or hot water) during a washing cycle. In other embodiments, aplurality of NCE layers can be arranged, with different active agentslayered in between. Such NCE layers can have the samerelease/redispersion properties or different ones, which can allow fordifferential release of the different active agents, consistent with theselected application.

LCST polymers can be used in the laundry or soap or other cleaningsheets together or singularly, and their ratios can be chosen based upontheir lower critical solution temperature, or the temperature at whichtheir hydrophilicity transitions. The amount of plasticizer can also beadjusted to fine-tune the timing when the sheets dissolve. Moreover,tuning dispersibility by varying types and amounts of LCST polymers canbe useful for applications which require different temperatures andadjusting the amount of plasticizer can allow for faster or slowerdissolution.

In embodiments, an NCE-based matrix containing soap products along withfragrances, emollients, and the like, can be formulated for convenientuse while traveling, so that it delivers the active agents upon contactwith water, thereby allowing handwashing, dishwashing, etc., withoutpreliminary reconstitution. As is discussed below in more detail,additives such as colors and fragrances can be incorporated in anNCE-based matrix using oil-based or water-based delivery vehicles, toaffect the properties of the matrix, to accompany other active agents orto act as primary active agents themselves. As used herein, acolor-producing additive can be any pigment, dye, fragrance, or othercolorant that changes the perceived color of the matrix or article byabsorbing or scattering different wavelengths of light along the visiblespectrum. A variety of color-producing additives, for a variety ofindustrial, household, cosmetic, fabric, and other products, arecompatible with the NCE-based formulations and matrices disclosedherein.

For example, a sheet or a formed article (e.g., a ball or cube) can beformed using an NCE-based matrix with a fragrance in the matrixinterstices that can be used for odor control purposes, for example in aclosed space. In more detail, an NCE-based matrix can be used to includeodor-blocking chemicals or natural scents adapted for release in closequarters that have high levels of odoriferant materials, for example inclosets, gym bags, suitcases, etc., or adapted for use in personalarticles likely to be odorific (e.g., shoe inserts or liners). The NCEmatrix adapted for these purposes can incorporate plasticizers or otheradditives to tune the release of the anti-odor agents or to adapt theirrelease to certain environmental conditions (for example, shoe linersthat emit odor-control substances when in contact with body-temperaturefeet). Analogously, an NCE-based matrix can be formulated with adeodorant or antiperspirant substances in the matrix interstices, withthe NCE-based matrix serving to permit a more durable application ofsuch products to the skin.

The base formulation for odor-control articles can include a NCE sourcetreated with a plasticizer such as glycerol and a cellulose polymer suchas methyl cellulose, with a ratio of these two actives to dry NCEs inthe range of 1:1 to 12:1. This creates the NCE base matrix, in whichother, more hydrophobic chemicals such as aromatics and oil-based scentscan be suspended, producing a more hydrophobic environment that canoffer additional advantages such as preventing breakdown from moistureor from contact with aqueous solutions.

Whether intending to control odor, mask odor, or produce odor, theseodor-related active agents (e.g., anti-odor, odor-masking, or odor(fragrance)-producing agents) can be mixed into the NCE base matrix at adesired concentration (e.g., in a range between about 1% and about 30%or between 10% and about 20%) to achieve the necessary scent strength.When finished, a viscous liquid is formed that is spreadable to formsheets having a thickness that can typically range from 0.1 mm to 3 mm,or the viscous liquid can be formed into any other desired shape byusing techniques familiar in the art for forming articles. For films orsheets as described above, after spreading they can be dried in a lowtemperature oven to form a dry, paper-like layer that can be usedseparately or incorporated into other articles of manufacture. Articlesthus formed, whether flat sheets or three-dimensional shapes, canconstantly release the desired odors at a rate determined by the amountof plasticizer used. The flexible geometry that a sheet provides can beuseful in harder-to-access areas, such as sneakers or thin crevices in ahousehold. It is understood that different geometries will distributescents differently. In embodiments, scents can be suspended inside thesesheets or shapes, for example, in a pod or a casing.

In embodiments, a variety of scents can be employed with the systemsdisclosed herein. The term “scent” as used herein refers to the varietyof odors that can be deliberately incorporated in and delivered by thematrices, shapes, and vehicles as described. For example, pleasantscents can be employed for cosmetic or aesthetic purposes, or tocamouflage unpleasant odors. Scents can be employed for medical,veterinary, or agricultural purposes, to act as insect repellants,pesticides, pheromones, growth hormones, or the like. Scents can besourced from volatile aromatic compounds, such as essential oils,hydrosols, perfume microcapsules, etc. Exemplary sources can incorporatebiological oils and chemical sources suspended in solution for easyapplication or mixing. Other sources for scents can be aqueous-based,such as hydrosols. The biodegradable nature of the NCE-based vehiclesmakes them especially useful for delivering scents or other activeagents that are to be released naturally into the environment: thedecomposition of the vehicle (e.g., a sheet) facilitates the release ofthe active agent: the rate of release can be controlled through carefulselection of the active agents and vehicle components, with amodification of the ratios of each component.

Other examples of scent-based technologies based on the formulationsdisclosed herein include without limitation insecticides for theagricultural sector, perfumes and odor neutralizers for household use,and pet hormones to encourage calm behavior around the home. Bycontrolling the rate of release through careful manipulation of the basetechnology, the applications can be personalized for various consumerneeds, for example, for agricultural products that release pesticidesquickly during planting season and more slowly when the plants are fullygrown.

In embodiments, a NCE matrix containing agricultural active ingredientscan be applied to agricultural products to be used in treating them,where such treatments can include those additives, fertilizers,pesticides, hormones, nutrients, or other treatment agents intended toimprove the life or health or post-harvest condition of the agriculturalproduct, or to ameliorate an adverse condition pertaining to theproduct, as would be understood by artisans of ordinary skill in theart. As an example, a NCE matrix containing agricultural activeingredients can be used as a spray-on coating for plants or seeds. Forliving plants or plant materials, a NCE matrix can contain active agentsintended to repel or kill insects, fungi, and the like, or can containnutrients or other beneficial agents, or other agricultural activeingredients. For seeds, NCE coating can be used to mark or designateseeds, allowing color grading or other differentiation, or can repelmoisture, dust, or other physical contaminants. NCE matrices can supportactive agents intended to enhance growth or protect against pests andfungi, including sustained release formulations of such active agents,and can furthermore protect against mechanical damage. In embodiments,the NCE matrix for seed coating can contain precisely formulated agents(such as fertilizers, micronutrients, crop protection chemicals andbiologicals, temperature-sensitive polymers, water-retention materials,colorants, and beneficial organisms, etc.), which can be dispensed overappropriate time intervals following application. NCE matrices canfurther be formed into structures that can support preloaded seeds atprecisely positioned spacings, with nutrients, fertilizers, orprotective substances like weed-killers embedded within the matrices andoptionally combined with materials that can retain water around the seeditself, thereby facilitating seed planting and optimizing seed growth.

For example, as described previously, matrices comprising odoriferantmaterials can be readily formed from NCE matrices, optionally incombination with plasticizers to control the release of the odoriferant.This technology can be adapted for agricultural purposes, for examplewith the use of pheromones as the agricultural active ingredients.Pheromones are understood to be secreted or excreted chemicals thattrigger a social response in members of the same species. While they maynot possess “odors” as the term is commonly understood, pheromonereceptors are typically located in the olfactory epithelium orvomeronasal organ, indicating that they are processed by similarpathways as conventional. Pheromones are thus considered odor-relatedactive agents for the purposes of the present disclosure.

It is known that certain pheromones have use in the agriculturalindustry as pesticides or artificial growth hormones. Pheromones can besuspended in NCE matrices and formed into sheets or formed articles,whereby the pheromones are released into the environment at a controlledrate as the NCE matrix decomposes. The rate of release can be controlledthrough the careful selection of plasticizer and modification of theamount of it in the matrix substrate. Hydrophobicity can be controlledthrough the selection of an additive imparting hydrophobic properties tothe matrix, such as a cellulosic polymer additive (e.g., a more or lesshydrophobic polymer). NCE matrices containing more hydrophobic materialswill take longer to break down, releasing the pheromones into theenvironment at a slower rate, encouraging long-term growth. Anadditional advantage of this technology is the contribution of celluloseto the soil, which encourages the activity of helpful insects in theenvironment to aerate the soil and break the cellulose down into usefulmaterials such as carbon dioxide for the plants.

It is understood that other active agents having agricultural effectscan be similarly incorporated into NCE matrices for applications togrowing plants. For example, in embodiments, growth hormones can beincluded in the matrices and released in a controlled manner, asdescribed above. In other embodiments, insecticides, fungicides,pesticides, and the like can be incorporated into NCE matrices. Forthese purposes, the matrix itself can include plasticizers to facilitatethe diffusion of the active agents into the ambient air if this is theappropriate mechanism of action; such plasticizers can advantageously behygroscopic to help the diffusion of the active agents if they are to beairborne. In order to hold the active agents within the NCE matrixwithout premature release and without damaging the matrix itself, thematrix material can be thickened using a thickening agent such ascellulose polymers, starch, gelatin, or the like. Similar technology canbe used for insect repellants, such as DEET, permethrin, picaridin, andthe like. These materials can be incorporated into NCE sheets andapplied directly to the skin or to articles of clothing. As the sheetdissolves, the residual active agent is deposited locally, continuing toprovide insect repellent activity. Appropriate selection of plasticizerscan prolong the release of the insect repellants, to prolong protection.

In addition, matrices used for agricultural purposes can be coated withor formulated with hydrophobic components to protect the agriculturalactive agents and prevent them from being washed off after application.This ability to protect the active agent and provide for controlledrelease can be useful for dispensing fertilizers to plants over aprolonged or predetermined period of time. By contrast, currentfertilizer formulations are water-soluble, so that they can be easilywashed away on rainy days. It is understood that a more hydrophobicselection of components for the NCE vehicle (promoted with the selectionof more hydrophobic cellulose materials, such as methyl cellulose, orwith the addition of oils or waxes) will take longer to break down in amoist environment, such as in the ground or in an area with highhumidity, releasing the pesticides, hormones, fertilizers, etc., intothe environment at a slower rate, encouraging long-term growth. Anadditional advantage of this technology is the contribution of celluloseto the soil, which encourages the activity of helpful insects in theenvironment to aerate the soil and break the cellulose down into usefulmaterials such as carbon dioxide for the plants. The NCE-basedtechnology disclosed herein can cooperate with the agricultural activeagents to encourage healthy growth of plants for stronger, more abundantcrops.

ii. NCE Matrices as Structures: Dissolvable Properties

NCE matrices have mechanical properties due to their incorporation ofthe NCEs themselves in a structural framework. The matrices can thus beused as supporting or enveloping structures for formed articles thathave advantageous mechanical properties such as strength and stabilitybut that are also engineered to be dissolvable at an appropriate timefor consumer use.

This property allows containers to be constructed that have sufficientdurability to retain their contents during consumer use, but furthermoreto allow for their ready decomposition and biodegradability after use.This property allows containers to be constructed for more ephemeralpurposes, such as a container for a fertilizer or agricultural productthat is intended to dissolve over a short period of time in order torelease the product into the environment. This property also allowscontainers to be constructed for immediate dissolving upon encounteringwater, for example for delivering active agents for laundry or otherhome care purposes.

As an example, sheets, strips, and the like formed from a NCE matrix canbe used to provide wrappers or containers for enveloping or otherwisedelivering active agents within, thus providing an easily dissolving(dispersible) vessel for useful materials, allowing such materials to bedispensed conveniently by the consumer. For example, active agents suchas a cleaning product, a laundry detergent or a dishwasher soap can beenclosed in a biodegradable sheet comprising a dispersible NCE matrix.One or more compartments can be formed with the NCE-based wrappingmaterial so that the various active agents can be kept separate, ifneeded, within a single article. In embodiments, sheets formed from NCEmatrices can be joined together to form containers for enveloping activeagents such as laundry products as a payload within the closed NCEenvelope; such sheets can themselves also contain active agents in theirinterstices, so that more than one type of laundry product is delivered,with each one kept separate from the other(s). A differential solubilityprofile can permit the active agent in the NCE-matrix sheet itself to bedelivered first, followed by sufficient dissolution of the encapsulatingsheet structure surrounding the payload to impair its integrity andpermit delivery of the payload.

In embodiments, an NCE-based wrapping material can enclose a paste orgel comprising a laundry detergent or other cleaning product, forexample in powdered or in gel or liquid form, optionally including otheractive agents such as bleaches, enzymes for stain removal, fabricsofteners, and the like. In embodiments, active agents such as areexemplified above (e.g., cleaning or laundry products) can be envelopedin an NCE-based wrapper to form a pod-like container for the activeagents. In an embodiment, a wrapper formed from a NCE matrix sheet canwrap completely around the product, or a wrapper can be positioned aboveand below the active agent and sealed to enclose the active agent.Sealing the two NCE wrapper sheets can be performed using heat(searing), or by applying a natural polymeric adhesive to stick themtogether. In embodiments, a thin and lightweight sheet formed from aredispersible matrix and weighing about 1 gm can be shaped as a pod oran envelope to contain up to about 30 gm of a detergent powder in itsinterior. In other embodiments, the NCE based matrix can be extrudedfrom a circular die as an open, elongate tube. The tube with or withoutactive agents inside can be cut to desired lengths whose ends can besealed by pinching, searing, or gluing. Alternatively, the hollow tubecan be cut to the desired lengths, with one end sealed, following whichthe desired ingredients are loaded in the hollow interior.

In yet other embodiments, the NCE-based matrix can be used as a wrapperor a container for a cleaning product such as a toilet bowl cleaner,allowing the fabrication of a disposable, biodegradable toilet cleaningpad or cleaning brush that be used instead of the conventional systemfor toilet bowl cleaning comprising a reusable brush and a cleaningproduct to be dispensed in the toilet bowl. In such an embodiment, thecleaning product can be enveloped within one or more external NCEmatrices to form a single-use, flushable, biodegradable cleaning pad orbrush, which can be attached to a wand, extendible member, or otherapplicator by the user before employing the cleaning pad to scrub thesurfaces of the toilet. At the conclusion of the cleaning process, thecleaning pad can be detached from the applicator to be flushed away withthe water in the bowl that has been used for rinsing off the cleaningproduct. Advantageously, the cleaning pad can be detachable by the userthrough a mechanism on the proximal end of the applicator, so that theuser need not directly contact the flushable pad or brush to remove it.As an additional advantage, the NCE-based matrix containing the cleaningproduct can have abrasive properties (as described below in moredetail), and those properties can be optimized so that the scrubbingsurface of the pad is adapted for cleaning the surfaces of the toiletbowl. This system, comprising an applicator and a flushable pad orbrush, is a hygienic alternative to conventional toilet bowl cleaningsystems because there is no multiuse toilet brush that must be stored inbetween exposures to the contaminated surfaces in the toilet. Instead,the applicator can be made of a smooth plastic material that resists theattachment of contaminated material; contaminants instead remainattached to the NCE-based matrix exterior of the cleaning pad, and thepad itself is flushed away. The biodegradability of the NCE-based matrixallows the pad to decompose quickly after cleaning has beenaccomplished, to minimize the risk of obstructing plumbing afterflushing.

A paste or gel to be enclosed within the dispersible NCE-matrix-basedcontainer can be formed by suspending the active agents in a vehicleformed from a water-soluble, non-aqueous, viscous liquid polymer such aspoly(propylene) glycol, polyethylene glycol, polyethylene oxide,polyoxyethylene, and the like, and their derivatives. A thickening agentcan be optionally added that is soluble in the water soluble,non-aqueous, viscous liquid polymer, for example cellulose polymers suchas hydroxypropyl methyl cellulose, methyl cellulose, etc., optionally incombination with a dispersible (i.e., water soluble), hygroscopicplasticizer such as glycerol. In embodiments, the paste or gel can beformed by combining detergent and a cellulose polymer or combination ofpolymers in ratios between 8:1 and 15:1, with a range of a 2:1 ratio to8:1 ratio of a dispersible viscous polymer to the active modifiers ofthe cellulose polymer and hygroscopic plasticizer, and a ratio between50/50 and 95/5 of cellulose polymer to hygroscopic plasticizer. Acomposition comprising these substances can create a highly viscous,gel-like medium within which cleaning or laundry products such asdetergents, bleach, enzymes, fabric softeners, and the like can besuspended. In embodiments, a powdered or other concentrated form (e.g.,concentrated liquids, gels, emulsions, and the like) for the activeagent(s) offers advantages, for example, allowing the co-presence withinthe gel of several different chemicals that ordinarily cannot bephysically combined, due to their interaction if they are mixed togetheras aqueous fluids; in powdered or other concentrated form, thesechemicals can coexist within the gel, without requiring separatecompartments to keep them apart. Moreover, due to the powdered or otherconcentrated form of the active agent(s), the volume for each unit canbe decreased to improve shipping efficiency. This composition,containing the active agent(s) suspended or emulsified within the pasteor gel matrix can then be packaged within sheets or wrappers formed fromNCEs as described herein to create sealed single-use containers such assingle-chamber or multi-chamber pouches, pods, or otherwise suitablyshaped packets that can be put directly into the washing machine ordishwasher, using safe, biodegradable materials that dissolve readilyupon contact with water to release the contents. It is understood thatthe active agents dispersed in the polymer gel medium can be arranged inorder to facilitate specialized cleaning, for example, in layers, suchas a layer of bleach-containing gel being attached to detergent gel forextra strength cleaning, and they can be separated by layers of sheetmaterial in between.

The NCE-based wrapper encasing the active agent(s) can be furtherengineered to tune the release of the active agents, for examplecreating a time-release container or a container that requires a certainwater temperature before dissolving. In embodiments, this timed, ortuned, release can be done by adjusting the amounts of celluloseadditives (dispersant material) that is able to dissolve at differenttimes. For example, one or more LCST polymers can be used to form theNCE-based wrapper, and their ratios can be chosen based upon their lowercritical solution temperature, or the temperature at which theirhydrophilicity transitions. The amount of plasticizer can also beadjusted to fine-tune the timing for dissolution of the wrapper.Moreover, tuning dispersibility by varying types and amounts of LCSTpolymers can be useful for applications which require differenttemperatures and adjusting the amount of plasticizer can allow forfaster or slower dissolution, for example if wrappers with differentproperties are used for segregating different compartments containingdifferent active agents.

iii. NCE Matrices as Structures: Barrier Properties

NCE matrices prepared for use as containers or as films can be optimizedfor these applications to impart oil and grease resistant (OGR)properties and/or water-vapor or water resistant (either, WVR)properties to the NCE-based structures. WVR properties are oftenmeasured by the water vapor transmission rate (WVTR), which measures amaterial's water vapor permeability in units of gm/m²/day, or in g/100in²/day. Collectively, those coatings, formed articles and materialtreatments that improve resistance to oil and grease permeability and/orthat improve resistance to water vapor permeability, and/or that improveresistance to other fluids (liquids or gases) are termed “barriertreatments,” or “barrier-producing” materials. The resistance toselected fluids that they impart to the formed substance or substratematrix, such as OGR and/or WVR properties, are termed “barrierproperties.” Barrier properties can be tuned to permit differentialpermeability of various fluids, or selected degrees of permeability ofvarious fluids. As an example, in embodiments a barrier-producingformulation may impart both OGR and WVR properties to the article ittreats, with the relative strength of each property being tunable byadjusting the ingredients selected for the formulation itself, and/or byadjusting the relative amounts of its ingredients, for example toemphasize hydrophobicity or oleophobicity.

In embodiments, barrier formulations can be prepared to emphasize OGRproperties or WVR properties or both; in embodiments, barrierformulations can include both types of properties, and the formulationcomponents can be tuned to accentuate either the OGR or the WVRproperties or to balance them. The barrier formulation can comprise suchingredients as NCEs, cellulose polymers, filler particles, plasticizers,film-forming biopolymers, and the like, with different constituents anddifferent amounts of such constituents being selected to emphasize theOGR or WVR features in the barrier treatment, as applicable to theparticular article being treated and formed. For example, a range ofcellulose polymers exists, with the various polymers having differentdegrees of hydrophobicity or oleophobicity, so that a cellulose polymercan be selected to produce the desired degree of OGR and/or WVR. OGRtechnologies may include cellulose derivatives, and specifically onesthat are more hydrophobic. Overall, the cellulose derivatives previouslydescribed are oleophobic (hydrophilic), so it would be beneficial to mixin other materials that are more hydrophobic into the matrix to providemore water resistance, or overall more OGR/VWR. For example, methylcellulose provides good oil/grease resistance, but not as muchwater-resistance. A mixture of methyl cellulose and cellulose acetatecan be provided to tune for both OGR and WVR properties. LCST polymersdiscussed work well for oil resistance, but the films/coatings createdwith them are soluble at room temperature, causing water resistanceproperties to be less efficient. Cellulose acetate and lipids are someexamples of additives that can be used to tune OGR coatings to be morehydrophobic, and the combination of this with a more oleophobic materialcan provide both oil and water resistance. Similarly, certain fillershave more hydrophobic or oleophobic properties: for example, a fillersuch as wax can be selected to increase hydrophobicity, or, for example,a large surplus of NCEs can be added as pore-blockers to increaseoleophobicity. Fatty acids may also be used to increase hydrophobicity.Advantageously, the barrier formulation can be sprayable to permit easyapplication, whether to the surface of a formed article or to thesubstrate itself for mixing in.

In more detail, depending on the balance and amounts of ingredients,barrier treatment agents can be formulated for use in three generalcategories: 1) having a barrier profile with balanced OGR and WVRproperties, and both OGR and WVR to an effective degree; 2) having someWVR but substantial OGR; and 3) having some OGR but substantial WVR.Articles treated with Category 1 barrier formulations can be used forapplications such as food packaging in which both oil repellency andwater repellency are advantageous. Articles treated with Category 2barrier formulations can be used for those applications in which oilresistance is the more important attribute, for example in containersfor oils or greasy materials, and for packaging for premeasured amountsof oil-based products such as salad dressings or cosmetic lotions, orfor use as more durable vessels that can contain motor oil and similarfluids, instead of the metal containers in use for this purpose.Articles treated with Category 3 barrier formulations can be used forthose applications in which water repellency (even waterproofing) is themore important attribute, for example in coffee cups and six-packholders for beverage cans, or in grocery bags and other containers orwrappers intended to be substantially water-resistant or leak-proof

In embodiments, film-forming biopolymers can be added in barrierformulations, for example in those formulations intended for mix-in use.As used herein, the term “biopolymer” refers to those polymers that areproduced by a living organism during its lifespan. Such biopolymers caninclude, without limitation, exopolysaccharides such as bacterialcellulose, kefiran, pullulan, levan, gellan, and other polysaccharidessuch as alginate, celluloses, carrageenan, gum Arabic, starch and plantglycomannans-like locust bean gum, mannan, guar gum, and the like.Biopolymers can also include biopolyesters such aspolyhydroxy-alkanoates and polylactic acid derivatives. Advantageously,certain exopolysaccharides such as pullulan, kefiran, cellulose, levan,gellan, and the like can be used to form films, such as are used inpackaging applications. The addition of biopolymers useful as filmformers or having other useful mechanical or barrier properties canallow the barrier formulation to be tuned and customized for particularpurposes.

In embodiments, additional measures may be useful to address theporosity of the NCE matrix within which the formulation is to besupported. Additions to the base formulation can be provided, forexample stearic acid or other long-chain fatty acids to enhance thebarrier's hydrophobic properties, or wax beads as pore fillers toproduce a more hydrophobic base substrate for formed articles.

Under certain circumstances, pore closure within the matrix isadvantageous to permit the barrier treatment to work effectively or toimprove its efficacy. If pore closure is desired, barrier treatmentformulations (for example, comprising cellulosic polymers with varyinghydrophobicity, plasticizers, and NCEs) can be used in combination withadditional pore closure materials, such as filler particles to block thepores within the NCE matrix to improve the ability of the matrix toblock oil, grease, and/or water. Such filler particles can include,without limitation, large or small particles of any shape, or mixturesof different sizes and shapes, made from natural or artificialmaterials, including organic or inorganic components; by way ofillustration, particles useful for this purpose can comprise, withoutlimitation, sand materials, ceramic materials, resinous materials, glassmaterials, polymeric materials, rubber materials, organic materials suchas nutshells that have been chipped, ground, pulverized or crushed to asuitable size (e.g., walnut, pecan, coconut, almond, ivory nut, Brazilnut, and the like), seed shells or fruit pits that have been chipped,ground, pulverized or crushed to a suitable size (e.g., plum, olive,peach, cherry, apricot, etc.), chipped, ground, pulverized or crushedmaterials from other plants such as corn cobs, specific particles suchas solid glass, glass microspheres, fly ash, silica, alumina, fumedcarbon, carbon black, graphite, mica, boron, zirconia, talc, kaolin,titanium dioxide, calcium carbonate (e.g., precipitated calciumcarbonate (PCC)), calcium silicate, and the like, as well ascombinations or composites of these or similar different materials.Advantageously, in certain embodiments filler particles can be selectedthat can be hydrophobic in nature, or that can be made hydrophobic(e.g., functionalized PCC), for example by linking or coating them witha hydrophobic material such as stearic or oleic acid. In embodiments,the filler particles can comprise waxes, either as the substance for theparticle itself or as a coating for other particles, and these waxes canbe in wax form or emulsion form (oil in water wax emulsion). Forexample, a waxy substance such as beeswax, soybean wax, carnauba wax,and the like, can be used, either as a base particle or as a coating forother filler particles. As used herein, the term “wax” refers to anyhydrocarbon that is lipophilic and a malleable solid near ambienttemperatures, typically having a melting point above about 40° C. Asexamples, waxes can include long-chain aliphatic hydrocarbons typicallyhaving 20-40 carbon atoms per molecule, or fatty acid/alcohol esterstypically containing from 12-32 carbon atoms per molecule, such asmyricyl cerotate, found in beeswax and carnauba wax. Filler particlescan be mixed into the barrier formulation to impart pore-cloggingfunctionalities.

With or without the presence of pore-clogging filler particles, it isdesirable in certain embodiments to prepare the barrier formulation as aviscous suspension; it has been determined, for example, that viscosityenhances the pore-clogging feature of the formulation and improves itsoil-and-grease-resistant properties. However, in other embodiments, itis advantageous to prepare a more dilute suspension, for example whenused as a mix-in formulation: in embodiments, using a less viscousbarrier formulation can improve the mixing of the barrier-producingingredients with the pulp or pulp-based matrix substance being used forshaping the formed article. As used herein, the term “pulp-based” refersto those materials that have been derived from pulp by processing,forming, or treating while retaining pulp or pulp derivatives withintheir substance. Pulp and pulp-based materials can be used with theformulations, compositions, and methods disclosed herein, to be formedor shaped as components of or substrates for articles of manufacture inany useful shape, such as sheets, fibers, solid articles, moldedarticles, etc.

In embodiments, NCE-based OGR and WVR materials as disclosed herein canbe used as barrier treatments, such as (i) coatings on top of the matrixor on top of articles made therefrom to impart barrier propertiesthereto, (ii) mix-in additives incorporated in other compositions orsubstances that are themselves used to form articles, to impart barrierproperties thereto, (iii) films or packages that possess barrierproperties, for containing other substances or materials, or (iv) anycombination of the foregoing. In more detail, OGR and/or WVRformulations can be used as coatings, or can be mixed into an NCE-basedslurry and be shaped (e.g., thermoformed) into a product. For example,in embodiments, containers formed from NCE matrixes can be preparedhaving OGR properties and/or WVR properties, enabling the containers tosecurely confine and deliver liquids or gels to the consumer for otherpurposes.

In embodiments, the barrier-producing ingredients can be mixed into theNCE-based matrix formulation (as described above) at any concentration;then, before molding/thermoforming takes place, the mixture can beheated to just above the lower critical solution temperature of the LCSTpolymer component of the barrier formulation. This procedure allows theLCST polymer dispersed within the mixture to precipitate (or “crashout”) onto the surface of the fibrous, NCE-bearing matrix. In otherembodiments, the barrier-producing formulation can be applied moresuperficially to an article of manufacture, using conventionalapplication procedures such as painting or blade painting, curtaincoating, and the like, or spraying if the formulation is of a viscositythat is compatible with the selected spraying apparatus.

A film, sheet or formed article having barrier properties providesimportant advantages when employed in commercial products. For example,an OGR or WVR pouch, pod, or other packaging article formed from NCEs asdescribed herein can serve as a container for condiments, dressings, orother liquid or gelatinous food substances, allowing the consumer toopen the package and dispense the food substance as desired. Suchpackaging can conveniently contain and dispense aqueous or oil-basedfood substances like soy sauce, ketchup, mustard, mayonnaise, saladdressings, dairy products, and the like, thereby reducing the plasticwaste associated with conventional packaging for such food substances.

The NCE wrapper material can be tuned to maximize other protectiveelements of the package, to optimize oil resistance for oils or oilsuspensions or to optimize water resistance for aqueous solutions orsuspensions, to add strength, or to reduce gas permeability to providefor more hermetic packaging properties. For example, wrappers and sheetsformed from NCEs having OGR and/or WVR properties can be used ascomponents of or entire containers for liquids such as milk (e.g.,shelf-stable milk cartons), to be sterilizable by techniques such asultraviolet sterilization and other methods familiar to artisans ofordinary skill. In embodiments, these OGR and/or WVR packaging materialscan be transparent or translucent, with superior mechanical propertiessuch as tear resistance or rigidity, offering a viable alternative toconventional packaging and hermetic films made from polyolefins. Inembodiments, the OGR and/or WVR materials incorporating NCEs, asdisclosed herein, can be modified by adding additional polymers orparticles to the matrix material (e.g., PVA, PVOH, hydroxyethylbutyrate, exfoliated clay, and the like), to improve their hermeticproperties.

iv. NCE Matrices as Structures: Intrinsic Properties

NCE matrices possess certain intrinsic mechanical properties, includinghardness, toughness, brittleness, stiffness, cohesion, durability,impact resistance, optical transparency, and the like, that can also beimproved or tuned for specific applications by incorporating NCEsprepared as disclosed here, optionally in conjunction with appropriatesecondary additives. Such intrinsic mechanical properties can beexploited in useful articles. These intrinsic mechanical properties canbe advantageous alone, or in combination with other characteristics ofNCE matrices such as their ability to act as carriers, to act asdissolvable containers, or to act as oil, grease, and/or water-resistantbarriers. In embodiments, an NCE matrix can be prepared havingadvantageous intrinsic mechanical properties for a particularapplication, while also providing a suspending framework for embeddedactive agents.

For example, by engineering the intrinsic mechanical properties of theNCE matrix to achieve a desired degree of hardness, strength, andtoughness, nano-scaled abrasive compositions can be formed. It isunderstood that, during abrasion, the surface of the abrasive materialforms an irregular interface with the abraded surface that causesparticles on the abraded surface to be torn off or worn down. Since theNCE matrix is formed with its surface irregularities on a nano-scaleorder of magnitude, these matrices can be engineered for applicationsrequiring minimal, gentle abrasion. As examples, an NCE matrix can beused for minimal abrasion as a removal pad for face makeup, or a pad forskin exfoliation. In other embodiments, an NCE matrix can be combinedwith soap products or body/facial cleansers as an exfoliant. In yetother embodiments, the NCE matrix can be used for minimal abrasion toremove dental plaque in dentifrices for oral hygiene, or as dentalproducts for professional use. An NCE matrix formulation can beparticularly advantageous for dental products such as toothpaste ortooth powder by allowing the abraded dental plaque to adhere to theextensive surface area of the matrix itself to facilitate the removal ofthe plaque particles. In yet other embodiments, an NCE matrix can beused to abrade uneven or damaged biological surfaces as may be found onbones or in blood vessels. In embodiments, the NCE matrix used forabrasion purposes can support embedded active agents, such as ananticoagulant agent to be applied to an abraded arterial plaque toprevent subsequent adherence of platelets during the healing period.

Appropriately engineered NCE matrices are suitable for use as householdscrubbers, cleaners, and wipes. For example, an NCE matrix material canbe shaped as a scrub or a sponge, optionally preloaded with cleaningchemicals. In such articles of manufacture, the NCE architecture canprovide an extensive surface area within the matrix, permittingextremely high capture of oil, grease, dirt, or other spilled materialswhile also providing abrasiveness that facilitates scrubbing. As afurther advantage, the NCE matrix is itself made of plant-derivedproducts, and is disposable and compostable.

Appropriately engineered NCE matrices can be readily transformed intosheets or liquid foams that can be dried to form substitutes forconventional articles such as paper packaging or Styrofoam. Non-foamedsheets can be used as substitutes for paper wrappers, butcher paper,sandwich wraps, and the like, where the properties of a foam are notneeded; foams can be used in specialized situations where propertiessuch as thermal insulation are advantageous, or where the light weightper unit of volume is advantageous, as in packing peanuts. Inembodiments, barrier properties can be introduced into the foam usingthe techniques for rendering the formulation more hydrophobic oroleophobic, as described above. In embodiments, oil and grease resistantproperties can be imparted to the foam by rendering some or all of theNCE particles more oleophobic, and/or by using the matrix to supportoleophobic coating materials, and/or by introducing other oleophobicadditives; similarly, water-vapor resistant properties can be impartedto the foam by rendering some or all of the NCE particles morehydrophobic, and/or by using a matrix to support hydrophobic coatingmaterials, and/or by introducing other hydrophobic additives. Asdescribed herein, foamed or non-foamed formulations can be customized toemphasize either the oleophobic or hydrophobic properties, and suchformulations can exhibit both types of properties to greater or lesserdegrees.

In more detail, materials comprising NCE matrices can offer replacementsto conventional foam products such as are found in synthetic Styrofoampacking materials. Conventional packing materials and containers arelightweight, cushioning, and water-repelling, thus well-adapted fortheir end-uses; however, these materials are made from petroleum-basedplastics like polystyrene, which cannot be recycled and which thereforeare relegated to landfills, where they take centuries to decompose.Foamed NCE matrices can offer biodegradable alternatives with goodintrinsic mechanical properties, or NCEs can be used with otherbiodegradable materials to improve their properties for uses such aspacking materials, as will be described in more detail below. In orderto form sheets or liquid foams, the NCEs to form the matrix can betreated to permit redispersibility, as described above. In embodiments,a slurry of 2-3% redispersed NCEs can then be mixed with a cellulosicpolymer and an optional plasticizer, and/or combined with a hydrophobicor oleophobic material in order to impart the desired barrierproperties; in other embodiments, the hydrophobic or oleophobic materialcan replace the cellulosic polymer, while in yet other embodiments, thecellulosic polymer itself can provide the desired hydrophobicity oroleophobicity. A barrier-producing additive, for example a hydrophobicstarch, a hydrophobic cellulosic polymer, a fatty acid, surfactant, or awater in oil or wax emulsion, can be added in ratios ranging from 1:1barrier additive to NCE to 15:1 barrier additive to NCE, and preferablyfrom 3:1 to 9:1. In embodiments, foaming can be produced easily with NCEsuspensions, because of the high viscosity of these materials and theirresponse to vigorous agitation or whipping, and barrier properties canbe readily introduced into the foam. Adding surfactants to an NCEsuspension can facilitate foaming. Once the NCE suspension has beenfoamed, flash-drying can lead to a locked-in foamy texture in sheets orformed articles. As examples, rolling up or vacuum molding unfoamed orfoamed sheets of NCE matrices can create thermally insulting,lightweight cups, plates, bowls, food wrappers, takeout containers, ortrash bags having the added advantage of biodegradability as anNCE-based product. As an example, high efficiency, lightweight, thermalinsulation can be produced from a dried NCE foam, with barrierproperties (OGR and/or WVR properties) available as optional,customizable features.

The durability of the NCE matrix when dried on the skin can support avariety of other cosmetic and medical products, including withoutlimitation, bandages and wound dressings based on NCE matrices bearingdisinfection or coagulation aids, vehicles for sustained delivery ofhealth or wellness agents such as insect repellants, anti-itchmedications, analgesics, topical anesthetics, CBD oil and the like, ordiagnostic products or monitors, e.g., for glucose monitoring, ionicconductivity, pH, and the like. In other embodiments, the NCE matrix canbe ingestible, for use e.g., with probiotics or pharmaceuticals,providing controlled and slow release.

The use of NCE matrices is particularly advantageous with active agentsin certain personal care applications because of the opticaltransparency of the NCE suspension, for example hair hold formulationand cosmetics. In embodiments, shampoos, hair conditioners, hair hold,and hair color preparations can be formulated by including the activeagents within the NCE matrix, with the matrix then drying as atransparent layer on the underlying hair shaft surface. Hair productsfor temporary hair styling can also use NCE matrices for retaining hairin a particular shape or style. In more detail, it is understood thathairspray, mousse, gels, and the like have been designed and are used tohold many different hairstyles in place for hours at a time. Theseconventional products tend to use harsh chemicals to provide desired“hold,” and products lacking this category of chemicals tend not toproduce satisfactory hair hold: they may not hold as well, or they mayprovide a “crispy” feeling to the hair, or they may produce a stiff orunnatural look. As an alternative, NCE matrix formulation can includeactive agents such as chitosan that allow the NCE matrix to adherefirmly to hair strands and to impart shape-hold benefits. The productcan be washed out of the hair with water and ordinary shampoo. AnNCE-based formulation with the addition of chitosan or similarreinforcing secondary additive can produce durable hair hold with asoft, natural feel, without employing harsh chemicals.

While the NCE matrix can be used with a single active agent, it can alsosupport combinations of hair care products within a single formulation,for example a shampoo, conditioner, and shape-hold agent all applied atonce as a single product. NCEs can also be used to impart color ontohair in an easy, gentle manner without the use of harsh chemicals. Inother embodiments, NCEs can be precolored before being suspended, and/orcan incorporate color-bearing particles such as lignins within theirmatrices, allowing convenient application to hair, for example to darkengrey hair, without requiring the harsh chemical treatments used inconventional products.

In other embodiments, NCE matrix formulations can be used for applyingcosmetic or skin care (i.e., treating skin disorders or skin conditionssuch as wrinkles or hyperpigmentation) products. As an example, a skincream can be formulated by suspending skin-treating substances (such asvitamins, lipoic acid, collagen, emollients, sunscreens, and the like)in the NCE matrix, to form a product that is invisible on the skin afterapplication due to the optical transparency of the NCE matrix. Asanother example, NCE-based creams or lotions can be spread on the skinsurface to smooth it and flatten out wrinkles. With higherconcentrations of NCEs, the formulation contracts as it dries and pullsthe skin taught; with appropriate positioning and directionalorientation of the applied formulation, it can exert a force thatcounteracts skin wrinkling or that offers a smoothing of the skinsurface. As yet another example, an NCE matrix for a sunscreen orsunblock is particularly advantageous, because of its intrinsic strengthfollowing application, so that it forms a durable layer of sunscreenprotection on the skin. In embodiments, pigments can also be added tomask the chalky appearance of sunblock agents such as zinc oxide ortitanium dioxide. As another example, a skin cream or face mask can beformulated as a shape-hold material that temporarily flattens wrinklesafter application and drying, due to the strength properties of the NCEmatrix once dried; in embodiments, the matrix can be engineered tocontract upon drying, thus exerting force on loose or wrinkled skin inadvantageous directions.

Vehicles can be prepared for medical skin treatments or transdermalpharmaceutical delivery using NCE matrices. Pharmaceutical products,nutraceutical products, moisturizers, antioxidants, and the like can beincorporated into NCE matrices and applied to the skin so that theactive agents can pass through the matrix into the skin. As an example,an application of a NCE matrix containing moisturizers, antioxidants andtopical retinol could be used as an overnight mask, which would keep theactive agents in place while offering a dry external surface forcontacting bedclothes. Similarly, a NCE matrix can be used for applyinga pharmaceutical or other beneficial product to a localized area of theskin. Topical products for acne or rosacea (such as salicylic acid,azelaic acid, topical retinoids, benzoyl peroxide (for acne),metronidazole, ivermectin, (for rosacea), topical antibiotics (for both)embedded in a NCE matrix can be applied to affected areas for localtreatment. While the NCE matrix is typically translucent or transparent,pigments can be included to render the product opaque and conceal thelesions undergoing treatment.

NCE matrices can be engineered for transdermal delivery ofpharmaceutical products, especially those used as sustained releaseagents. As examples, active agents such as nicotine, opioids, hormones,nitroglycerin, methylphenidate, MAO inhibitor antidepressants,clonidine, scopolamine, Vitamin B12 and cyanocobalamin, and the like,are compatible with delivery as transdermal patches that can be formedfrom NCE matrices. For certain applications, the patch formed from NCEmatrices can support an array of microneedles, thus forming amicroneedle transdermal patch that can be used for controlled release ofother pharmaceutical products. The presence of the NCEs in these patchproducts can improve the strength and durability of the patches.

A variety of biomedical and cosmetic articles of manufacture canincorporate NCEs as a matrix for the delivery of medical or cosmeticactive agents and can further incorporate NCEs as a filler for strengthenhancement. When used as a matrix, NCEs can form the framework forroll-on, spread-on, or spray on patches or liquid bandages. Such devicescan be used to deliver pharmaceutical, nutraceutical or cosmeticproducts as active agents, including collagen, vitamins, retinoids,hyaluronic acid, and the like. Such products can be delivered as aliquid form factor, for example as a concentrate that can be furtherdiluted or as a ready-to-use liquid, or as a solid form factor to bedissolved or suspended in water by the consumer, who then applies thereconstituted formulation to the affected area. In embodiments, the NCEscan be applied to form a film, i.e., a continuous layer over theaffected area, to cover and protect skin injuries to encourage healing.A liquid NCE-based formulation can dry to form a thin, solid, flexibleprotective barrier, optionally transparent or translucent so thathealing can be monitored. Antiseptics or antibiotics or otherspecialized active agents can be included in the formulation to preventor combat infection in the area covered by the barrier.

NCE formulations having oil, grease, and/or water-resistant propertiescan be combined with NCE matrices, so that the film applied to the skinis more likely to stay in place and resist wear and tear. Forapplications incorporating NCEs as delivery vehicles for active agents(such as creams, patches, bandages, and the like), the OGR/WVRcomponents of the formulation can prolong the useful life of the producton the skin. For example, adding OGR/WVR formulations to the NCE matrixbearing the active agent is useful for those topical applications(whether for medical or cosmetic purposes) for which an enduring periodof skin contact is desirable. OGR/WGR formulations can also be added tothose compositions used for transdermal patches to protect the patchesfrom water, perspiration, skin oils, and the like that might otherwiseloosen the patches and interfere with the delivery of their activeagents.

NCE vehicles applied to the skin can be used for other applications,such as semipermanent tattooing, or the application of conductive linesor shapes to the skin to interface with sensors to communicateinformation (for example, as RFID tokens for wireless pay, portablemedical records, biometrics, health monitoring, etc.). Other NCE-basedformulations can be used for specialty inks, paints, adhesives, orconductive coatings or conductive elements, where the NCE matrixprovides support for the active agents or active particulate matter.

In an advantageous embodiment, lignin or other specialty substances suchas melanin or other dyes or pigments can be incorporated into matricesformed from suspended NCEs to produce pigmented formulations for use inhair, nails, fabrics, and the like. The natural affinity of NCEs withthe skin can support the development of nail formulations with pigmentsor other aesthetic elements within the NCE matrix to provide a strongand chip-resistant nail polish for cosmetic uses, or to treat fragile ordamaged nails, without requiring varnishes or harsh organic solvents. Inother embodiments, NCEs can be used as strengthening agents forconventional nail polishes to improve their strength and chipresistance, or to treat fragile or damaged nails.

In embodiments, a NCE matrix can be shaped to provide the structural andarchitectural features for a particular article of manufacture. As anexample, a foamed NCE matrix, optionally combined with materials such ashydroxyapatite, can provide a strong bone graft that can act as ascaffold for osteoblasts to inhabit to produce bone tissue.Alternatively, the NCE matrix can be shaped as a solid bone graftwithout foaming but with the inclusion of other strengthening and/orbone-forming substances within the matrix. In embodiments, NCE can alsobe used as a scaffold for biomaterials that are not intended to degradequickly, such as surgical meshes, semi-permanent sutures, or scaffoldsfor bioengineered implants, due to the durability of NCEs within thebody. In embodiments, the NCE substance can be engineered to have moreor less biological durability, depending on the envisioned application.In embodiments, the NCE matrix can also be formed as threads, elongatedfibers, and the like, for specialty applications. As an example, spunthreads formed from the NCE matrix can be used alone or with integratedprotein materials such as collagen as dissolving suture materials orbiocompatible meshes, with customizable rates of decomposition andcustomizable strength engineered into the materials for specific uses.

b. NCEs as Additives in Composite Materials: General Characteristics

In embodiments, a population of NCEs can be incorporated into anexisting matrix composition (termed an “existing matrix”), for exampleorganic matrices such as paper matrices, plastic matrices, liquid resinmatrices, wood-based composites like TREX, and inorganic matrices suchas cement and plaster. Such matrices, formed with a redispersed orredispersible population of NCEs incorporated into an existing matrix istermed a “composite matrix.” In more detail, NCEs to be incorporated inan existing matrix to form the composite matrices can be provided asredispersible, dried NC-containing material with NC elements embeddedtherein as described herein, or they can be provided as NC elements thathave been redispersed and suspended in a redispersing formulation, asdescribed herein. In either case, NCEs so prepared and provided aretermed “additive NCEs” with reference to their inclusion in a compositematrix. Composite matrices therefore are understood to be combinationsof additive NCEs and existing matrix compositions.

In embodiments, the matrix-forming substances are coated with and/orimpregnated with additive NCEs to form the composite materials. As aresult, the composite materials can be equipped with specializedproperties that exceed those found in the original matrix-formingsubstance, or that are not found in the original matrix-formingsubstance. For example, the composite material can exhibit a specializedintrinsic mechanical property such as strength, hardness, toughness,brittleness, stiffness, cohesion, durability, impact resistance, opticaltransparency, and the like, where such a property exists in the originalmatrix-forming substance but where the presence of the NCEs in thecomposite article improves that specialized property. As anotherexample, the composite material can exhibit a barrier property such as ahydrophobic, oleophobic, or water-resistant property that can be presentin the original matrix-forming substance but is improved in thecomposite material, or that is absent in the original matrix-formingsubstance but is provided in the composite material. As yet anotherexample, the composite material can exhibit an adscititious property,i.e., a property that is not present in the original matrix-formingmaterial but that is produced through the use of the NCEs in theirordinary or modified state. Such an adscititious specialized property,i.e., typically absent in the original matrix-forming material butimported via the incorporation of a NCE formulation in the compositematerial, is electrical conductivity, which can be introduced into thecomposite material through the use of NCEs and the silver mirror effectand the like, as discussed below in more detail.

Specialized properties of composite materials using NCEs have alreadybeen contemplated in industry, but their use has been hampered by theredispersion problems mentioned previously. The redispersiontechnologies disclosed herein facilitate the transportation of NCEcompositions that can then be resuspended to be combined with othermatrix-forming materials, yielding composite materials. In embodiments,these redispersion technologies can produce a uniform mixture ofhigh-aspect-ratio NCEs within the primary matrix-forming material,allowing enhancement of desirable specialized properties in the finalcomposite, including intrinsic mechanical properties such as strength,hardness, toughness, brittleness, stiffness, cohesion, durability,impact resistance, optical transparency, and the like, as describedabove in more detail. In other embodiments, the use of NCE formulationsproduced using the redispersion technologies disclosed herein canintroduce or enhance specialized properties such as barrier propertiesthat allow the composite to have desirable degrees of oil and greaseresistance and/or water vapor resistance. In yet other embodiments, theuse of NCE formulations produced using the redispersion technologiesdisclosed herein can provide the composite material with a newspecialized property such as electrical conductivity that is not presentin the original matrix-forming material.

i. NCEs as Fillers: Exemplary Articles

Fillers are understood to improve mechanical properties of organic andin organic substances, or make the product cheaper, more lightweight,and the like. Fillers can improve composite properties such as strength,hardness, toughness, brittleness, stiffness, cohesion, durability,impact resistance, optical transparency, and the like. While NCEs havealready been used as fillers in consumer products, their use has beenlimited due to redispersibility problems described herein. The methodsfor NCE redispersion as disclosed herein can permit the more widespreadadoption of these additives as reinforcing agents for paper, resin,cement and plastic, and can further permit a dramatic expansion of newuses. As used herein, the term “reinforce” refers to an improvement ofan mechanical characteristic pertaining to strength, hardness,toughness, brittleness, stiffness, cohesion, durability, impactresistance, optical transparency, and the like, that is found in theexisting matrix; a composite matrix having improved mechanicalproperties as compared to the constitutive existing matrix can be termed“reinforced,” with the reinforcement of the composite materialattributable to the presence of the NCEs.

NCEs, although intrinsically hydrophilic, can be employed as fillerswithin a hydrophobic environment as well. For use in a hydrophobicenvironment, the NCEs can be surface-modified to match the properties ofthe hydrophobic matrix in which they are to be incorporated, so thatthey are compatible with the matrix and can be evenly dispersed withinit. In embodiments, surface modification of additive NCEs prepared inaccordance with the methods disclosed herein can be performed, forexample using a hydrophobic monolayer on the NCEs. Such NCEs that havebeen hydrophobized for use in hydrophobic matrices are not onlyredispersible upon drying (like unmodified NCEs in a hydrophilicenvironment) but also, by virtue of their hydrophobic coating, they arecompatible with various polymeric, “plastic” matrices, such asthermoplastic and thermoset matrices (e.g., polypropylene, polyethylene,polystyrene, polyesters, poly(acrylates/methacrylates), rubbers,silicones, urethanes, epoxies, and the like, to yield strong andlightweight non-porous solids for molding or extrusion, and open-cell orclosed-cell foams for other applications. In embodiments,hydrophobically-modified NCEs can offer renewable, lightweight,high-performance fillers for advanced composite hydrophobic materials,for uses such as vinyl siding, decking flooring, composite roofing,injection-molded plastic parts, automobile bumpers, fenders anddashboards, reinforced Styrofoam products such as insulation blocks andceiling tiles, and the like. In other embodiments, NCEs can be dispersedwithin adhesives that are generally added to matrix materials such asoriented strand board or other wood-based building materials, therebyimproving the strength of the adhesive itself and the strength of thematrix materials.

The lightweight and environmentally friendly nature of NCE reinforcingfillers is especially suitable for medical uses, in which NCEs can beused to add strength to medical articles, such as may be intended fortemporary use. For example, NCEs can be added to cast material tostrengthen it without adding weight. As another example, NCEs can beadded to bandage materials to strengthen them. When incorporated in aconventional bandage or a hydrogel bandage, NCEs make the bandage moredurable while adding some structural protection to the healing wound.Similarly, NCEs can provide reinforcement when used in cosmeticproducts. Patches bearing pharmaceutical, nutraceutical, or cosmeticactive agents can obtain significant strength enhancement with low dosesof NCEs dispersed through the product. NCE fillers can be used withconventional polymeric matrices such as hydrogels, polyethylene, PVC,and other dressing materials, allowing improved strength and durabilitywhile permitting lighter and thinner bandages. NCE fillers can also beused with NCE matrices, as discussed previously, to improve strength anddurability. Similarly, cosmetic products such as face masks, nosestrips, and acrylic (faux) nails can benefit from the adhesive andstrength imparting properties of NCE fillers.

As another example, NCEs incorporated into other polymeric matrices asfillers can offer an environmentally attractive option for strengtheningrecreational equipment articles. In embodiments, an NCE-strengthenedpolymer can serve as a substitute for the synthetic materials used insurfboards and boat hulls (such as fiberglass resins, polyurethane orpolystyrene foam cores (surfboards), carbon fiber, fiberglass,polyethylene (sculls)), retaining strength with less weight, and in amore environmentally conscious manner. NCE additives can also be used toimprove strength and elasticity in recycled plastics. They can alsofacilitate the transition from petroleum sources of plastic materials tomore sustainable sources of plastics, which often lack the performancecharacteristics of the petroleum-based materials. For example, Lego hasexperimented with using biopolyethylene derived from sugar cane, but maybe unable to use this material as a substitute for the petroleum-basedacrylonitrile-butadiene-styrene (ABS) copolymer that is used to form itsbricks; NCE additives can improving the toughness and strength ofmaterials like biopolyethylene, allowing the reinforced, bio-derivedcomposites to be used as potential replacements for materials like ABS.

As yet another example, for athletic shoes, soles can be made fromNCE-strengthened polymers or as composites using NCE matrices, in orderto reduce the amount of materials such as ethyl vinyl acetate andpolyurethane and silicone gels used in the shoes, thus offering a moreenvironmentally friendly product. NCE matrix foams or foams containingNCE reinforcing fillers can be used in these applications, providingsupport and comfort for the wearer. This inclusion of NCEs can increasethe bend-twist-tear resistance through the strengthening effect of thefibers while also keeping the sole of the shoe lightweight andshape-holding. As an added benefit, viscoelastic dampening can beimparted by the matrix of fibers throughout the sole, interrupting thetransfer of physical shockwaves through the sole and into the wearer'sbody with small, rigid fibers to absorb parts of the physical force.

As a further example, architectural paint products containingresuspended NCEs can be formulated to be inherently primed, allowingimmediate use on drywall, wood, concrete, brick, and the like. Thepresence of the NCEs in the paint product can provide improved substrateadhesion and drip suppression, crack resistance, and resistance tocorrosion. Other opportunities exist for improving constructionmaterials by incorporating NCEs, for example, to producehigh-performance materials such as sag-free stucco, lightweight andstrong sheetrock (dry wall), oriented strand board and similarcomposites, faux-wood-concrete countertops that have are easy to processand crack-resistant, synthetic flooring and bath tiles, plastermoldings, joint compounds, artificial-lightweight sculpted stones,recycled-glass-cement-NFC/MFC composites, and the like. Opportunities tocreate durable inks that can be used on compostable products also existthrough the use of NCE-filled resin. Wheeled vehicles, such asautomobiles, trucks, aircraft, ATVs, motorcycles, scooters, bicycles,wheelchairs, and the like, can also benefit from NCE-filled tires toimprove wear resistance, strength, and durability. Lightweight, foamedversions of NCE-containing materials can be formed for specificapplications.

NCEs can be used as fillers in a variety of environments, as theforegoing examples demonstrate. Once redispersed, the NCEs can beprovided with an appropriate coating to enable them to interact with theselected polymeric matrix. They can thus add strength and elasticitywithout weight to composite materials that incorporate them. They canalso substitute for existing fillers in order to provide a plant-derivedalternative to conventional petroleum-derived or inorganic fillers. Forexample, 3D printing materials are typically plastics like ABS,polylactic acid, polyvinyl alcohol, polyethylene terephthalate glycol,nylons, and a variety of resins, which can be reinforced with fillerslike carbon fibers, Kevlar, fiberglass and the like. NCEs can besubstituted for the inorganic fibers as more sustainable components ofthe overall 3D printing substrate.

ii. NCEs as Matrix Pore-Closers: Exemplary Articles

The nano-dimensions of NCEs enable them to be incorporated within thepores of existing matrices to produce advantageous properties for theresulting composite article, where their advantageous properties arebased on their presence within the pores to decrease the porosity of thenative matrix. In embodiments, NCEs can thus be used as a coatingproduct for existing matrices, like paper products, to fill the pores inthe paper matrix to create high-value, specialty paper products. As anexample, a paper product with NCEs embedded in its pores can offer oiland grease resistance. As another example, a paper product with embeddedNCEs in its pores can be engineered to form a releasable label backingor selective adhesive. In embodiments, all forms of cellulose,hydrophobic emulsions, fatty acids, any film-forming material, etc., canbe used for these sorts of applications, where NCE-based formulationsare used to provide advantageous properties in composite articles. Allsuch additives can be used alone as a single additive, added together,or added sequentially.

iii. NCEs as Substrate Components: Exemplary Articles

While films, sheets, formed articles, and the like, can be formedsubstantially entirely from NCE matrices, as described above additiveNCEs can be integrated into existing matrices made from other polymericmaterials to produce composites having advantageous and/or specializedproperties. Such existing polymeric matrices receptive to the additionof additive NCEs prepared by the methods disclosed herein can beprovided as formulations suitable for the incorporation of the additiveNCEs, and optionally including other additives having advantageousproperties. By selection of appropriate polymers and additives for theexisting matrix within which NCEs are integrated to form a compositematerial, properties such as structural strength, resilience,elasticity, water resistance, oil and grease resistance, and the like,can be imparted to useful articles formed therefrom, in combination withbiodegradability. These polymeric matrices and formulations to whichadditive NCEs are added in order to produce composite matrices aretermed “constitutive polymer substrates (CPS).”

In embodiments, addition of NFC/MFC to a CPS can be done directly fromlow concentration suspensions (˜2 wt %) or may be added in dried formwith redispersion additives to cut down on water, cost, and to enhanceredispersion. The final NCE-containing polymer formulation can beprepared at high concentrations for extrusion processes on an industrialscale. The extruded films can then be dried and/or molded into theirfinal geometries (for bags, lids, containers, films, etc.). Illustrativeexamples are provided below.

(a) Example: Films and Sheets

As an example, films used as wrappers for food products can be madeusing a combination of conventional biodegradable, naturally derivedmaterials such as cellulose ethers, cellulose esters, starch ethers,starch esters, polyvinyl alcohol, hydroxyethyl butyrate, or anycombination thereof, with NCE and dispersant additives as describedabove incorporated to impart intrinsic mechanical properties to thefilms, including without limitation, improved mechanical strength fortear resistance and rigidity. In embodiments, the NCE additives can befibers coated with films to provide oil and grease resistance and/orwater resistance. Cellulose acetate, or other hydrophobic, stretchymaterials, can be added to impart elasticity onto the coated fibers, orcan be incorporated into the polymer matrix to provide flexibility andstretchiness for the products. For products that require gas-barrierproperties, polyvinyl alcohol or copolymers of polyvinylacetate/polyvinyl alcohol are advantageous.

Composite films or sheets incorporating NCEs can be transparent ortranslucent as desired, with superior mechanical properties such as tearresistance, along with biodegradability. By contrast, plastic films andsheets, such as are used for Ziplock bags, garbage bags, grocery bags,and the like, are typically formed from polyolefins such as polyethyleneand polypropylene, which are petroleum-derived and slow to degrade. Inembodiments, films and sheets formed by incorporating NCEs as describedherein can be used for a multitude of other packaging applications wherestrength is desirable, to provide a biodegradable alternative toconventional polyolefin-based packaging materials. Such films and sheetscan also be formed with barrier properties (e.g., OGR or WVR or both),using the techniques disclosed herein. Such a composite, comprising NCEsprepared according to the methods disclosed herein and having barrierproperties, is termed a barrier material. Barrier materials canadvantageously be formed as films, sheets, containers, or other articlesof manufacture in which designated barrier properties are desired.

In more detail, in embodiments, a barrier material can be prepared froma base formulation of biodegradable materials such as cellulose ethers,cellulose esters, starch ethers, starch esters, polyvinyl alcohol,hydroxyethyl butyrate, polyvinyl acetate, or any combination thereof,with additives to impart specific properties to meet a particular need.For example, for a barrier material requiring gas-barrier properties caninclude polyvinyl alcohol, polyvinyl acetate, copolymers thereof, andblends thereof. For water and oil repellency, methyl cellulose is adesirable additive. To improve mechanical strength, NCEs can be added atconcentrations ranging from 1 wt % to 10 wt %. In embodiments, a baseformulation can be prepared with polymers with molecular weights rangingfrom tens of thousands g/mol to millions g/mol, with the specificpolymer(s) selected for optimal physical integrity; advantageously, highmolecular weight versions can be selected (for example, in molecularweight ranges from a hundred thousand g/mol to millions g/mol). Additionof plasticizers may be incorporated at concentrations ranging from, forexample, about 1 wt % to about 50 wt %, or about 1 wt % to about 10 wt%, or about 5% to about 15%, to impart flexibility. Plasticizers caninclude, but are not limited to 1,2-propanediaol, xylitol, erythritol,maltitol, and mannitol, or fatty acids such as caprylic acid, caproicacid, or the like. Fatty acids used as plasticizers may be beneficial ina barrier application due to its hydrophobic nature. Addition of NCEscan be done directly from low concentration suspensions (˜2 wt %), orcan be added in dried form and redispersed using the redispersing agentsas described herein. For large-scale processing, the full formulation(including redispersion polymer(s), NFC/MFC, plasticizers, and desiredadditives) can be mixed in a large tank and pumped to an extruder with aslit die. Extruded sheets may then be pressed and/or perforated withrollers. After drying (heated rollers or ovens) the pressed sheets canbe collected into rolls or further shaped into bags or sachets.

An exemplary formulation to produce wrappers or containers or sachetsfor non-oxygen sensitive substances (e.g., salt/pepper) can include thefollowing ingredients (by weight, based on a total formulation weight of100 g):

-   -   Methyl cellulose (MC): 85.5 g    -   Xylitol: 4.5 g    -   NCE: 10 g

An exemplary formulation to produce wrappers or containers foroxygen-sensitive materials (e.g., see-through films for meat trays) caninclude the following ingredients (by weight, based on a totalformulation weight of 100 g):

-   -   Polyvinyl alcohol (PVA): 23.75 g    -   Polyvinyl acetate (PVAc): 23.75 g    -   Methyl cellulose (MC): 42.75 g    -   Maltitol: 4.75    -   NCE: 5 g

(b) Example: Fibers and Nonwoven Fabrics

In embodiments, the formulae used to produce films and sheets reinforcedwith NCEs can be used to create other useful shapes or forms, such asthreads and fibers. The formulae previously described can be used incombination with NCEs as the composite substrate material that can beformed into strong, biodegradable fibers that can be used for manyapplications, such as (without limitation) healthcare specialty products(sutures, meshes, implantable drug dispensing vehicles, and the like),nonwoven materials (wipes, coffee filters, tea bags, cloths, dryersheets, and the like), and fibrous reinforcers for building or packagingmaterials to add strength, shock absorbency, and resiliency.

As described previously, an NCE matrix useful for these purposes can beformed as an NCE material alone. However, this section exemplifiesproducing a composite material incorporating NCEs in a polymeric matrixmade from other, non-NCE substances. For example, a composite materialcan be formed as previously described, using a natural, biodegradablepolymers as disclosed herein to form the CPS, to which NCEs can be addedto improve strength, toughness, brittleness, stiffness, cohesion,durability, impact resistance, and the like. The CPS can alsoincorporate other secondary additives to impart advantageous specializedproperties to the overall composition, such as mechanical properties,barrier properties (e.g., hydrophobicity/hydrophilicity, oil and greaseresistance, and the like) and adscititious properties (e.g., electricalconductivity, elasticity, malleability, and the like). The final CPS,with all desired additives and with the NCE inclusions, can then beformed into a variety of useful articles.

In embodiments, the composite described above can be formed into fibersor non-woven materials. As a first step, a CPS, for example a viscouspolymer formulation comprising one or more biodegradable polymers, isprepared. Biodegradable polymers that can be used in the CPS for thispurpose include such polymers as polyvinyl alcohol that is fully orpartially hydrolyzed, polyvinyl acetate, cellulose derivatives(cellulose ethers and esters, such as methylcellulose (MC), hydroxyethylcellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropylmethylcellulose (HPMC) and the like), polylactic acid, polygalactic acid,polyhydroxybutyrate, polyvinylpyrrolidone, and mixtures thereof.Polyvinyl alcohol is advantageous for certain applications due to itsoxygen impermeability. Other natural polymers that can be used in theCPS include chitosan, zein, pectin, and natural proteins (soy, whey,pea, and the like).

NCEs can be added into the CPS to impart specialized properties,including intrinsic mechanical properties, barrier properties, andadscititious properties. A desirable specialized property is anintrinsic mechanical property such as extra strength, hardness,toughness, brittleness, stiffness, cohesion, durability, impactresistance, or a selected optical property such as transparence,translucence, and the like. Once included in the CPS, the NCEs canremain deployed as fibers and can align with themselves in a straight orrandomly oriented way, to form networks or other internal architecturewithin the CPS. In embodiments, an amount of NCEs in the final substratecan range from about 1 wt % to about 30 wt %.

Before or after the addition of the NCEs to the CPS, certain of theformulation's specialized properties can be optimized. In embodiments,the optimized specialized property is a mechanical property. Inembodiments, the optimized specialized property is a barrier property.In embodiments, the optimized specialized property is an adscititiousproperty. The optimization of the CPS can result in a formed article orarticle of manufacture, such as fibers or non-woven fabrics, havingoptimized specialized properties.

As an example, the hydrophobicity/hydrophilicity of the CPS can beadjusted, depending upon the final application, by the addition ofsubstances selected to impart those desired properties such as increasedstrength or tuned hydrophobicity/hydrophilicity. For a more hydrophilicfiber, biodegradable gums or other hydrocolloids can used in conjunctionwith or to replace the biodegradable polymers mentioned above, forexample adding xanthan gum to the CPS or replacing certain of theconstitutive polymers in the CPS with xanthan gum. For a morehydrophobic fiber, biodegradable polymers that are more hydrophobic,such as methylcellulose, may be used; in addition or alternatively, toimpart additional hydrophobicity, small amounts of very hydrophobicmaterials, such as waxes, oils, or emulsions thereof, can be added. Ifwaxes are added, the CPS can tend to form an emulsion instead of asuspension, in which case surfactants such as fatty acids or others canbe used to enhance the incorporation of the waxes into the overall CPS.

After a CPS has been formulated to incorporate the NCEs and anydesirable secondary additives, it provides a viscous substrate forfurther shaping, for example for forming fibers. Optionally, glycerol,or other small molecules that interact with the constitutive polymerchains or that insert themselves in between them can be added to thesubstrate to act as plasticizers, which can result in the formation of aless brittle, more malleable fiber once shaped. Plasticizers that can beused including without limitation such previously mentioned substancesas glycerol, propanediol, erythritol, xylitol, mannitol, maltitol,sorbitol, and the like, as well as fatty acids such as stearic acid,palmitic acid, myristic acid, lauric acid, capric acid, caprylic acid,caproic acid, and the like.

After the composite matrix (i.e., the suspension of the NCEs in aconstitutive polymer formulation, with appropriate secondary additives)has been formulated, it can be shaped using techniques familiar in theart for processing viscous or melted substrates to form fibers. In moredetail, the substrate can be prepared at a suitable viscosity so that itcan be directed through an extruder or a spinneret system. Thesubstrate's viscosity can be adjusted by adding more or less water toit, by incorporating secondary additives, including thinning orthickening agents, by changing its temperature, or by other mechanismsfamiliar in the art.

Once the composite matrix has attained a suitable viscosity, it servesas an amorphous substrate that can be forced through an extruder or aspinneret, i.e., a die comprising a number of holes or channels. Passageof the amorphous substrate through the extruder or the spinneret holesresults in the elongation of the substrate to form one or more fibers.As would be understood by skilled artisans, the number of holes in aspinneret can produce a defined number of fibers that can be entwinedwith each other in a subsequent step to form a yarn or a thread. Aswould also be understood by skilled artisans, a single-hole extruder canbe used to form a continuous single fiber or thread, which cansubsequently be divided mechanically into smaller fibrils, for exampleby cutting the single fiber longitudinally or transversely. Inembodiments, the NCE fibrils can align directionally within the singleor multiple extruded polymeric fibers to enhance their resistance totransverse or longitudinal stress.

Following the extrusion process, the fibers can pass through a region tosolidify the fibers for their intended uses. For example, if the fibershad been derived from a heated substrate and they still retain heatafter extrusion, they can be cooled to the temperature of their intendeduse or re-heated as necessary, e.g., to drive off excess water. Or, forexample, if the extruded fibers are still excessively pliant orstretchable, they can be hardened by exposure to a coagulant bath tocrosslink some of the component polymers, or to an air gap that drivesoff volatile components of the substrate and allows subsequentcoagulation. Following the optimization of the extruded fibers, they canbe combined to form a yarn or a thread, which can then be furthertreated with a spinfinish as needed, in keeping with techniques familiarto skilled artisans. The yarn or thread can be further processed usingone or more godet rolls running at appropriate speeds and temperaturesin order to align the polymeric materials with each other and with theNCEs within the fibers and to eliminate voids within the fibers, therebymaking the material stronger. In embodiments, fibers or filaments madefrom biodegradable, NCE-containing CPS substrates as disclosed hereincan be used for a number of applications.

In embodiments, these NCE-containing products can be used to formbiodegradable non-woven materials, advantageously providing analternative to conventional nonwovens that are made fromnon-biodegradable materials like polypropylene or polyester. It isunderstood that nonwoven fabric can be formed from fibers or filamentsthat are attached together in a random pattern to form mats, without theneed of converting the fibers or filaments into yarns or braidedthreads. The formation of nonwoven fabrics is thus distinctive fromtraditional weaving, knitting, or braiding techniques for forming fibersor filaments into fabrics. Two major processes are involved in formingnonwoven fabrics: web formation and web consolidation. Using thesetechniques with fibers or filaments produced from NCE-containing CPSsubstrates can yield biodegradable nonwoven materials havingadvantageous properties. Web formation processes for producing suchbiodegradable materials would subject the fibers and filaments producedas described above to such techniques as carding, air laying, wetlaying, spun-bonding, melt-blowing and more recently electro-spinning,as would be understood by skilled artisans. Web consolidation processesfor producing such biodegradable materials can include such techniquesas needle-punching, spunlacing, chemical bonding, and thermal bonding.

Fibers or nonwoven materials formed from NCE-containing CPS substratescan produce fibers or fabrics that exhibit optimized properties such asfabric handling and drapability, tensile properties, abrasionresistance, pilling and washing stability, dyeing and printingadaptability, and other features that permit these biodegradablematerials to be used for a variety of applications. In embodiments, theproduct formed from these biodegradable materials is customized so thatit retains sufficient integrity and strength for its desired purpose,while being susceptible to biodegradability after it is discarded.Examples include, without limitation, products such as cleaning towels(analogous to microfiber cleaning cloths), wipes, absorbent materials,tea bags, coffee filters and similar food-related filters, filters forindustrial and consumer use including HEPA filters, vacuum bags, andmedical gowns, drapes, covers, masks, bandages and other wounddressings, and packaging systems, in addition to the aforesaid dryersheets and similar products.

As another example, artificial fabrics and fibers that are NCE-derivedcan be formed to produce an artificial leather. Conventional artificialleather is made by taking artificial fabric, such as polyester, andsoaking/coating it in polyurethane, polyvinyl chloride, or wax. Theseproducts have poor performance vs natural leather, and they are madefrom synthetic, non-biodegradable plastic materials. As an alternative,a naturally-derived artificial leather can be made using fibers orfabrics made from NCEs. As described above, NCE-based fabrics can beproduced that form the basic substrate for the artificial leather, whilereinforcement can be added from fibers spun from NCEs or added from NCEsthemselves acting as filler particles (or both). OGR/WVR coatings can beadded to the fibers, using the techniques described above. Celluloseacetate, or other hydrophobic, stretchy materials, can be added toimpart elasticity onto the coated fibers and therefore the final leatherproduct. The addition of strength from NFCs/MFCs, as well as theelasticity from the cellulose acetate can create a durable, naturallyderived leather alternative. Hydrophobic plasticizers, such as triacetinor citrate esters, fatty acids etc., can be used to impart elasticity aswell.

(c) Example: Drinking Straws

An application combining the features of biodegradability, strength, andbarrier properties is the use of NCE materials to form an article ofmanufacture formed as a biodegradable drinking straw. Because straws areintended to be used with a variety of liquids, including alcohol, fats,acids, and the like, at various temperatures, and because straws requiresufficient strength to resist deformation during normal use, there hasbeen a tendency to use more durable plastics that are not biodegradable;biodegradable materials alone lack the liquid tolerance and strength towithstand the stresses that straws typically encounter. The use of NCEmaterials alone or in combination with other biodegradable materials canprovide the necessary liquid tolerance and strength, while permittingthe product to be biodegradable. As described previously, the NCE matrixalone can be formed as a sheet and rolled into a hollow cylinder to actas a straw. In other embodiments, a composite material can be formed,for example using a derivatized cellulose such as methylcellulosecombined with NCEs, where the methylcellulose or analogous biodegradableLCST polymers or other materials like cellulose acetate, lipids,polyvinyl alcohol or copolymers of polyvinyl acetate/polyvinyl alcohol,waxes, wax emulsions hydrophobic starch, fatty acids, or otherhydrophobic cellulosic polymers, or any other similar hydrophobicpolymers can increase the hydrophobicity of the material.

In an embodiment, methylcellulose (MC), cellulose acetate, lipids,polyvinyl alcohol or copolymers of polyvinyl acetate/polyvinyl alcohol,waxes, wax emulsions hydrophobic starch, fatty acids, or otherhydrophobic cellulosic polymers, or any other similar hydrophobicpolymers in dry form can be combined with dried, redispersible NCEs thathave been pretreated with a redispersion additive, such as a combinationof a small molecule plasticizer and a biodegradable polymer such as acellulosic polymer as described above, with the MC and NCE mixture beingground into powder form. The powdered mixture can then be stirred intowater to create a viscous mixture that can then be formed as a sheet orextruded as a hollow cylinder. In embodiments, a ratio of theredispersion additive (e.g., small molecule and biodegradable polymer)to the NCE elements can be in a range from about 1:1 to about 15:1, orin a range from about 3:1 to about 12;1, or at a ratio of about 6:1 witha variety of balances between the biodegradable cellulosic polymer andthe small molecule plasticizer available, for example a 70/30 balance ofpolymer to small molecule, or a 50/50 balance between polymer and smallmolecule, or a 0/100 balance between polymer and small molecule, or anybalance of the two components in between the exemplary ratios provided.For embodiments engineered to have barrier properties, the ratio of OGRor WVR ingredients to NCEs can be from about 1:1 to about 12:1, orbetween about 3:1 to about 9:1. In another embodiment, a 2-3% suspensionof NCEs can be mixed with a MC or other cellulosic-containingsuspension. In embodiments, the NCE formulation can comprise CMFs aswell as CNFs, or can comprise more CMFs than CNFs, or can be consistessentially of CMFs, with the CMF to CNF ratio being adjusted tooptimize the strength of the final formulation. In embodiments, regularpulp can be used in addition to or instead of derivatized cellulose inthe mixture. Eliminating or decreasing the amount of the glycerol orother plasticizer used in the formulation can improve the stiffness ofthe straw product. Spun hydrogel fibers can be added to the composite toimprove strength and flexibility.

(d) Example: Biodegradable Alternatives to Conventional Products

As described previously, composite matrices as disclosed herein offerbiodegradable alternatives to conventional products.

For NCE/starch composites, cellulose microfibers are advantageous,either alone or in combination with cellulose nanofibers, as additivesto the starch-based CPS. Foaming can be produced by mechanical means, orby incorporating foam-forming elements such as surfactants in themixture. Bicarbonate crystals can also be incorporated into the mixtureas a foam forming element with a later addition of acid to activatefoaming. Secondary additives such as linseed oil or more hydrophobiccellulose additives, such as methyl cellulose, cellulose acetate,lipids, polyvinyl alcohol or copolymers of polyvinyl acetate/polyvinylalcohol, waxes, wax emulsions hydrophobic starch, fatty acids, otherhydrophobic cellulosic polymers, or any other similar hydrophobicpolymers can be added to improve hydrophobicity; alternatively or inaddition, the NCE additives can be prepared having OGR properties.

In embodiments, a composite matrix produced using biodegradablematerials as the existing matrix can be used to produce foams and foamedarticles. Conventional foamed products made from biodegradablematerials, for example foams formed from starches, typically have poorperformance relative to petroleum-derived foams, often lacking thestrength and hydrophobicity of petroleum-derived products. NCE-basedfoams, derived predominantly from NCE matrices can act as substitutesfor conventional foams for uses such as packing materials, as describedabove. Composite materials, comprising mixtures of NCEs andbiodegradable materials such as starches or derivatized cellulose (e.g.,cellulose ethers or cellulose acetate), can also be prepared as foamedarticles and can be similarly used as substitutes for conventionalfoams, combining the advantages of biodegradability with the desirablestrength, shock absorbency, light weight, and water resistance thatpacking materials and containers require.

In embodiments, redispersed or redispersible NCE additives preparedaccording to the techniques disclosed herein, can be used as carriers toimpart barrier properties onto biodegradable existing matrices such asthose formed from pulp or pulp-based materials. To do this, NCEs canfirst be treated in the same way as previously described to allow forredispersability. A cellulosic polymer mixed with a plasticizer can beadded to an as-received 2-3% NCE slurry, and it can be dried into asheet or into any other form or shape. Once dry, the product then can beground up into small particles resembling a powder. To this new powder,one or more hydrophobic or oleophobic materials can be added in order toimpart barrier properties. This barrier-producing material canadvantageously be somewhat soluble or solubilizable in water tofacilitate handling, for example a hydrophobic starch, a cellulosicpolymer that is more hydrophobic, such as methyl cellulosic, or a fattyacid. The barrier-producing material can be added in ratios ranging from1:1 barrier additive to NCE to 15:1 barrier additive to NCE, andpreferably from 3:1 to 9:1. The barrier-producing material can also bean oil-in-water emulsion or a wax emulsion. A secondary additive such asa plasticizer can be added in this step as well. The composition that isproduced is either a powder or paste material that can be shipped in itsconcentrated form and later dissolved into water to be added to aselected, biodegradable existing matrix to produce a composite matrixhaving barrier properties. For example, the slurry of ingredients can beused as a mix-in barrier additive for pulp-molded or pulp-based productsas described previously, or it can be used as a coating for analready-made pulp or pulp-based product, as described previously. It canalso be used to impart barrier properties to fibers: the compositematrix including the barrier treatment can be molded into a product,extruded to form fibers, spun into fibers, or otherwise processed toyield a composition or formed article possessing barrier properties. Thecomposition or formed article is then dried, allowing it to display thebarrier properties in dried form.

In embodiments, composite matrices can be produced from biodegradableexisting matrices having combinations of specialized properties, such asadvantageous mechanical properties and barrier properties. As anexample, packing materials can be formed from natural polymericmaterials as described previously, such as starch or derivatizedcellulose (cellulose ethers or cellulose acetate), with optionally addedbarrier polymers or optionally added barrier-treated NCE foam, whereinthe natural polymeric materials are reinforced with NCE-reinforcedfibers. In an embodiment, natural polymeric materials can be spun intothreads or fibers, with the NCE strands aligning within the spun fiberto create a strong, reinforced fiber. A foamed product such as a packingpeanut made of previously described natural material can be reinforcedwith these NCE-reinforced polymer fibers to form a packaging materialthat is a lightweight network with shock absorbing properties. Smallfibers or bunched-up balls of longer reinforced fibers can be used asreinforcement in the overall packing material matrix for increased shockabsorbency. NCE strands for this purpose can have intrinsichydrophobicity, and optionally can be treated with materials to improvetheir oil and grease resistance. Overall, these natural materials andNCE reinforcements (NCE fibers and/or NCE-reinforced polymer fibers) canbe used for many packaging applications, including in packing peanuts,bladders, cardboard boxes, etc.

(e) Example: Conductive Materials

In embodiments, the additive NCE population can include a subpopulationof NCEs that are modified via the silver mirror reaction to allow theiruse in conductive applications.

The silver mirror reaction produces a metallic silver layer on a surfaceas a result of a redox reaction by the interaction of an ammonia complexof silver and an aldehyde. The first stage of the silver mirrorreaction, using Tollen's reagent (an ammonia solution of silver oxide),is set forth in the following equation, EQ. 1:

Ag₂O+4NH₃.H₂O⇄2[Ag(NH₃)₂]OH+3H₂O  EQ. 1:

where [Ag(NH₃)₂] is silver diamine hydroxide, produced by the metaloxide dissolving in the ammonia solution.

The second stage of the silver mirror reaction, showing the reaction ofsilver diamine hydroxide and an aldehyde R—CH═O, is set forth in thefollowing equation, EQ. 2:

R—CH═O+2[Ag(NH₃)₂]OH→2Ag↓+R—COONH₄+3NH₃+H₂O  EQ. 2:

where [Ag(NH₃)₂] is silver diamine hydroxide, produced by the metaloxide dissolving in the ammonia solution, and where the products includea carbonic acid amine, an ammonia solution, and a silver precipitatethat forms the “silver mirror.”

If a subpopulation of NCEs, whether NFCs, MFCs, or mixtures thereof, aresoaked with an aldehyde so that the aldehyde groups are presented on thesurface of the NCEs, the redox reaction will occur on that the surfacesof these NCEs. Aldehydes useful in this reaction can includeglutaraldehyde, cinnamaldehyde, vanillin, or the like. Thesealdehyde-bearing NCEs can then be exposed to an ammonia complex ofsilver, resulting in the deposition of a silver sediment on the surfaceof the NCEs. As a result, a conductive and reflective coating can bedeposited on the NCE subpopulation. If this subpopulation is included ina composite matrix prepared as disclosed herein, the composite matrixwill have conductive properties, allowing it to be used in conductiveand/or reflective applications. As examples, conductive and highlyreflective NCEs can be used in applications where a combination ofstrength and conductivity are advantageous, for example, in fitness,health care and medical industries, as well as in cable cladding, EMIshielding, circuit board manufacturing, and overall electrodeconstruction. Other applications in which the elongated structure, highsurface area, and ability to be dispersed and coated offer advantageswould be apparent to those of ordinary skill in the relevant arts.

EXAMPLES

Materials used in Examples 1-4 include:

-   -   NFC suspensions in water (obtained from various sources,        including Performance Biofilaments, SAPPI, University of Maine,        and Auburn University)    -   Chemicals (all obtained from Sigma Aldrich unless otherwise        designated)        -   Tri(propylene glycol) butyl ether (TPnB)        -   Di(propylene glycol) propyl ether (DPnP)        -   Propylene glycol butyl ether (PnB)        -   Propylene glycol propyl ether (PnP)        -   Butylene glycol ethyl ether        -   Ethylene glycol monobutyl ether (2-butoxyethanol)        -   Propylene glycol monomethyl ether acetate        -   Propylene glycol diacetate        -   Ethylene glycol diacetate        -   Benzyl alcohol        -   1-heptanol        -   1-hexanol        -   Caffeine        -   Glycerol        -   Piperazine        -   Pyridine        -   Methylcellulose (MC)        -   Hydroxyethyl cellulose (HEC)        -   Hydroxypropyl cellulose (HPC)        -   Hydroxypropylmethyl cellulose (HPMC)        -   Poly(methyl vinyl ether)        -   Melamine        -   Triethanolamine        -   Dytek EP (1,3 diaminopentane)        -   Ethylenediamine        -   Diethylenetriamine        -   Tetraethylenepentamine        -   1,2-Diaminocyclohexane        -   Polyethyleneimine (PEI)        -   Ethylenediaminetetraacetic Acid (EDTA)        -   Luviskol Plus (polyvinylcaprolactam) (BASF)    -   Corning stir plate    -   BINDER forced convection oven

Example 1: Direct Additive Application into NFC Suspension

This experiment can test the direct application of redispersionadditives into NFC suspensions. In this experiment, a 2.1 wt % NFCslurry can be diluted to 0.1 wt % with tap water and stirred slowly forat least five hours to fully disperse the NFC fibers. 50 mL aliquots ofthe dilute NFC suspension can be measured and treated individually bydirect addition of the exemplary redispersion additives. Each additivecan be mixed directly into 50 mL of 0.1 wt % NFC suspension on a stirplate for five minutes. The resulting mixtures can be dried in a BINDERforced convection oven at 110° C. Following the drying, the resultingdry fiber mats can be submerged in 80 mL of tap water and resuspended ona stir plate for five minutes. The resuspended material can be evaluatedqualitatively, using the following criteria to assess the degree ofredispersion:

-   -   a) High redispersion efficacy: Complete detachment of the fiber        mat from the beaker well and total breakup of clusters/clumps        into discrete fibers, resulting in an opaque/translucent        suspension with no visible clots.    -   b) Medium redispersion efficacy: Moderate to complete detachment        of fiber mat from beaker well with small/medium NFC clots (1-5        mm diameter) suspended in aqueous media.    -   c) Low redispersion efficacy: Little to no detachment of fiber        mat from beaker well and presence of medium/large NFC clots (>5        mm diameter) suspended in aqueous media.

Expected results for redispersion efficacy for selected redispersionadditives are listed as follows:

-   -   HPC, HPMC, glycerol are expected to produce high redispersion        efficacy, added at amounts between 100% and 300% of the weight        of the NFCs in suspension.    -   Caffeine, ethylene diamine, tetraethylene pentamine, Dytek EP,        MC, Luvskol Plus, DPnP, and TPnB are expected to produce medium        redispersion efficacy, added at amounts between two times and        five times the weight of NFCs in suspension.    -   Other additives are expected either to yield low redispersion        efficacy and/or to require larger relative volumes of the        additive to produce a medium degree of redispersion.

Example 2: Binary/Tertiary Direct Additive Application into NFCSuspension

NFC suspensions, similar to those described in Example 1, can bediluted, stirred, and measured into 50 mL aliquots for treatment. Two orthree additives (binary or tertiary systems) can be combined to treateach NFC sample, following the methods set forth in Example 1. Alltreated samples can be dried and tested for redispersion following thesame protocols as Example 1. Redispersion efficacy for binary andtertiary systems can be predicted for various combinations of additives,using the redispersion efficacy criteria set forth in Example 1 toevaluate the effect of each combination of additives on redispersion.

The additive combinations can be introduced into the NFC samples invarious ratios. Additive combinations of HPC and HPMC in a 1:1 ratio canbe added in an amount three times greater than the amount of the NFCs inthe mixture, with an expected high redispersion efficacy. Additivecombinations of HPMC and MC in a 1:1 ratio can be added in an amountthree times greater than the amount of the NFCs in the mixture, with anexpected high redispersion efficacy. Other possible combinations areexpected to yield medium or low redispersion efficacy, and/or to requirefairly large amounts of additives in proportion to the amount of NFCsbeing treated. Potential combinations of additives are listed below inTable 1, with their predicted redispersion efficacy.

TABLE 1 Ratio of Ratio of Predicted Additives in Additives toRedispersion Additives Combination NFCs for testing Efficacy MC:HPC:HPMC1:1:1 3:1 Medium HPC:CMC 1:1 6:1 Medium HPC:CMC 1:1 3:1 Medium HPMC:CMC1:1 3:1 Medium MC:CMC 1:1 3:1 Medium HPC:MC 1:1 3:1 Medium HPC:PnP 1:512:1  Medium HPC:PnB 1:5 12:1  Low HPC:DPnP 1:5 0.60 Medium HPC:TPnB 1:50.60 Medium HPC:caffeine 1:2 0.15 Medium HPC:2-butoxyethanol 1:2 0.15Medium 2-butoxyethanol:PnB 1:1 1.00 Low 2-butoxyethanol:TPnB 1:1 1.00Medium 2-butoxyethanol:DPnP 1:1 1.00 Medium 2-butoxyethanol:PnP 1:1 1.00Low

Example 3: Unary treatment of post-filtered NFC

In this Example, a 1 L suspension of diluted NFC (0.3-1.0 wt %) can beprepared in accordance with Example 1, and combined with a dilute pulpsuspension (0.3-0.75 wt %). The combined stock suspension can beaggressively mixed on a stir plate for 15 min, and then it can befiltered through a 70-mesh screen in a Buchner funnel draining into a250 mL graduated cylinder to remove excess water, thereby forming anNFC/pulp mat on the mesh screen. Vacuum can be used to increase thefinal solids content of the NFC/pulp mat (˜10 wt %). The resulting matof NFC/pulp fibers can be thoroughly mixed with redispersion additivesfor testing, by mixing each selected additive into the filtered solidswith a spatula in a separate beaker.

Additives for testing redispersion capabilities can include LCSTpolymers and non-volatile additives. LCST polymers or non-volatileadditive candidates can first be dissolved into a concentrated aqueoussolution (ranging from 5 wt %-40 wt %) prior to adding them to theNFC/pulp solids. These solutions, each containing a single additive, canthen be added to the NFC/pulp solids material to treat them, usingmethods similar to those described in Example 1. All resulting samplesof treated NFC/pulp mixtures can then be deposited into silicone moldsof spherical hemispheres (1.5 cm diameter) and dried at 110° C.,yielding consistent sample shape, size, and density for comparisonpurposes.

Redispersion of the samples can be performed as described in theExamples above. The redispersion efficacy criteria set forth above canbe used to assess qualitatively the results of the redispersion tests.HPMC used in an amount of 1.5-2 times the amount of NFCs is expected toproduce low or medium redispersal efficacy, while glycerol in an amountof 3-4 times the amount of NFCs is expected to produce high redispersionefficacy.

Example 4: Binary Treatment of Post-Filtered NFC

In this experiment, NFC and pulp suspensions can be prepared andfiltered in accordance with Example 3. A treatment solution used to dosefiltered solid fibers can be prepared to include two active additives,such as HPMC and glycerol or HPMC and 2-butoxyethanol. Various ratios ofadditives and amounts of additives vs amount of NFCs can be tested. Itis anticipated that ratios of HPMC to glycerol between about 0.4:1 and2:1 would yield a medium or high redispersion efficacy, using thecriteria for qualitative results provided above, and a ratio of 0.6:1 ofHPMC to 2-butoxyethanol would yield a medium redispersion efficacy. Forthe HPMC:glycerol additive mixtures, a larger additive-to-NFC ratio, forexample 3:1, 4:1 or higher, would be expected to yield greaterredispersion efficacy than lower relative amounts of additives to NFCs.

Materials used in Examples 5-6 include:

-   -   Corning stir plate    -   BINDER forced convection oven    -   NFC (2.1 wt % in water): Auburn University    -   Sigma Aldrich Chemicals        -   Tri(propylene glycol) butyl ether (TPnB)        -   Di(propylene glycol) propyl ether (DPnP)        -   Propylene glycol butyl ether (PnB)        -   Propylene glycol propyl ether (PnP)        -   Butylene glycol ethyl ether        -   Ethylene glycol monobutyl ether (2-butoxyethanol)        -   Propylene glycol monomethyl ether acetate        -   Propylene glycol diacetate        -   Ethylene glycol diacetate        -   Benzyl alcohol        -   1-heptanol        -   1-hexanol        -   Caffeine        -   Glycerol        -   Piperazine        -   Pyridine        -   Methylcellulose (MC)        -   Hydroxyethyl cellulose (HEC)        -   Hydroxypropyl cellulose (HPC)        -   Hydroxypropylmethyl cellulose (HPMC)        -   Poly(methyl vinyl ether)        -   Melamine        -   Triethanolamine        -   Dytek EP (1,3 diaminopentane)        -   Ethylenediamine        -   Diethylenetriamine        -   Tetraethylenepentamine        -   1,2-Diaminocyclohexane        -   Polyethyleneimine (PEI)        -   Ethylenediaminetetraacetic Acid (EDTA)        -   Sodium dodecyl sulfate (SDS)    -   Other chemicals        -   Luviskol Plus (polyvinylcaprolactam): BASF        -   Capryl glucoside: Amazon        -   Decyl glucoside: Amazon        -   Coco glycoside: Amazon

Example 5: Treatment of Charged NCE Fibers

This experiment tested the direct application of redispersion additivesinto NFC suspensions. Soy hull was the bio source for the NCE fibers(NFCs), and it was mechanically and chemically treated by AuburnUniversity to create NFC suspensions at 2.1 wt % solids. Varying ratios,as set forth in Table 2 below of HPMC and glycerol were combined to formsolutions for treating the 2.1 wt % NFC suspension directly. The highlyviscous treated suspensions were subsequently spread over a siliconesheet at a thickness between 1 mm-3 mm and dried in the BINDER forcedconvection oven at 75° C., to yield NFC sheets.

The resulting treated and control NFC sheets were resuspended in glassvials with DI water at 5 wt % solids by shaking vigorously by hand forthree minutes. The vials were then observed qualitatively forredispersion efficacy, with the results set forth in Table 2 below. Thefollowing descriptions of redispersion efficacy were used to designatethe qualitative results observed from these redispersion tests.

Redispersion Efficacy:

-   -   a) High redispersion efficacy: Complete breakup of fiber sheet        into discrete fibers, resulting in an opaque/translucent        suspension with no visible clots.    -   b) Medium redispersion efficacy: Moderate breakup of fiber sheet        with small/medium NFC clots (1-5 mm diameter) suspended in        aqueous media.    -   c) Low redispersion efficacy: Little to no breakup of fiber        sheet and presence of medium/large NFC clots (>5 mm diameter)        suspended in aqueous media.

TABLE 2 Ratio of Total Additive Redispersion NFC (g) Additives AdditivesAmount (g) Efficacy 0.3 None N/A N/A Low 0.3 HPMC:Glycerol  1:19 0.9 Low0.3 HPMC:Glycerol  1:19 1.8 Medium 0.3 HPMC:Glycerol 19:1 0.9 Medium 0.3HPMC:Glycerol 19:1 1.2 Medium 0.3 HPMC:Glycerol 19:1 1.5 High 0.3HPMC:Glycerol 19:1 1.8 High

Example 6: Redispersion of Surfactant-Loaded Nanocellular Elements

This experiment utilized 2.1 wt % soy-hull-derived nanocellular element(NFC) suspension from Auburn University to serve as a carrier for achemical of interest (in this case, surfactants) when redispersed inwater. For this experiment, all NFC samples were dosed with redispersionadditives at a ratio of 6:1 with NFC fibers. The redispersion additivesconsisted of HPMC and glycerol at a ratio of 19:1, respectively.Following the direct application of the binary redispersion additivesolution to the 2.1 wt % NFC suspension to form a treated suspension,various surfactants were mixed, individually, into the treatedsuspension, with the resulting mixtures being dried, and tested forredispersibility according to the procedures outlined in Example 5. Theredispersibility was observed qualitatively according to theredispersion efficacy criteria set forth in Example 5. Table 3 belowlists the surfactants tested and their effects on NFC redispersion.

TABLE 3 Total Redis- NFC Surfactant persion (g) Surfactant(s) Ratio ofSurfactants Amount (g) Efficacy 0.3 SDS (only one surfactant used) 0.09Low 0.3 SDS (only one surfactant used) 0.20 Low 0.3 SDS (only onesurfactant used) 0.32 Medium 0.3 SDS (only one surfactant used) 0.45Medium 0.3 SDS (only one surfactant used) 0.60 High 0.3 Capryl (only onesurfactant used) 0.11 High Glucoside 0.3 Capryl (only one surfactantused) 0.23 High Glucoside 0.3 Capryl (only one surfactant used) 0.37High Glucoside 0.3 Capryl (only one surfactant used) 0.70 High Glucoside0.3 Coco (only one surfactant used) 0.70 Medium Glucoside 0.3 Decyl(only one surfactant used) 0.70 Medium Glucoside 0.3 SDS:Capryl 1:1 0.70High Glucoside 0.3 SDS: Coco 1:1 0.70 High Glucoside 0.3 SDS: Decyl 1:10.70 High Glucoside

Those samples that could be dried and redispersed with high redispersionefficacy yielded a thick surfactant-containing liquid that could beuseful as a soap. The results suggest that certain surfactants can beincorporated into redispersible NFC sheets to permit reconstitution asliquid surfactant-containing materials for uses such as soaps, shampoos,and the like. It is hypothesized that other active agents (inter alia,bleaches, cationic surfactants for fabric softening, fragrances,emollients, etc.) can be analogously incorporated into redispersible NFCsheets as well, alone or in combination with other ingredients.

Materials used in Example 7 include:

-   -   Corning stir plate    -   Soy hull NFC (2.1 wt % in water)(Auburn University)    -   Butcher paper—uncoated (Amazon)    -   DI water    -   Carrington Farms organic coconut cooking oil    -   Oven    -   Baking Pan    -   Sigma Aldrich Chemicals        -   Glycerol        -   Methyl cellulose (MC)

Example 7: Oil and Grease Resistance

This experiment tested the ability of treated NFC to impart oil andgrease resistance onto food contact paper. A soy hull NFC suspension(2.1% concentration) was used in this experiment. A 4.5% stock solutionof MC and glycerol in DI water was made on the stir plate, with 95% ofthe actives being HPMC and 5% being glycerol. 5-gram samples of the 2.1%soy hull NFC suspension were added to three small beakers, andcorresponding amount of MC/glycerol solution was added in with the NFCsuspension, leading to a 3:1, 6:1, and 9:1 treatment of activedispersant to dry NFC. The 3:1 sample included 7 grams of the 4.5%MC/glycerol solution, the 6:1 sample included 14 grams of theMC/glycerol solution, and the 9:1 sample included 21 grams of theMC/glycerol solution. There was also a sample with 5 grams of 2.1% NFCsuspension without any HPMC/glycerol treatment, but 7 grams ofadditional DI water was added to ensure a less viscous coating and tobetter match the viscosity of the other samples. This was treated as acontrol sample. The suspensions were mixed by hand and set aside.

Separately, uncoated brown butcher paper was cut up into small, 1.5″ by1.5″ squares. The four suspensions made in the previous step were eachpoured into its own weigh boat, and three different butcher papersquares were submerged (one at a time) in each suspension. Once eachsquare was fully submerged and fully coated, it was removed withtweezers and held above the weight boat for one minute to allow excesssuspension to run off the paper. Each piece of butcher paper was thenput in the oven to dry at 75° C. for 30-60 minutes. After the squareswere fully dry, three drops each of DI water and liquid coconut oil weredropped onto each square. The squares were observed at two intervals:immediately after the droplets of the water and oil were applied (Time1), and 15 minutes after the droplets were applied (Time 2). Whenobserved at Time 1 (immediately after the drops were applied), all foursamples appeared to repel water. The water droplets held their shape,and the contact angle (observed qualitatively) was relatively high andhad non-wetting characteristics. No color change occurred on the brownbutcher paper below the water droplet, indicating that the water dropletdid not penetrate the pores of the butcher paper. When observed at Time1, the oil droplets on the control sample had a contact angle(qualitatively observed) close to zero, as no droplet stayed presentabove the paper. The droplet spread out to a large area (roughly 3× thesize of the droplet), and the paper became wet and darker brown incolor, indicating that the oil penetrated the pores of the paper. The3:1 treated sample had a slightly higher contact angle than the controlsample, as the droplet remained visible, and the darker brown spot belowthe droplet was smaller than the control, roughly double the size of theoriginal droplet. The contact angle of the oil droplet on the 6:1 samplewas slightly higher than the one on the 3:1 sample, but otherwise lookedabout the same. The oil droplet on the 9:1 sample had the highestcontact angle of all samples, and no dark brown spot appeared below thedroplet, indicating that the oil did not penetrate the pores of thebutcher paper. When observed at Time 2 (15 minutes after the dropletswere applied), the water droplets remained the same as describedpreviously for all samples. When observed at Time 2, the appearance ofthe oil droplets had changed. The brown spot from the oil droplets fromthe control sample and the 3:1 sample had grown to cover about one thirdthe area of the square, indicating increased wetting over time. Thecontact angle of the oil droplets on the 6:1 sample had decreased overtime, and the brown spot from the droplets had grown to cover about onefifth of the area of the square. However, for the 9:1 sample, the oildroplet size and contact angle and lack of dark brown spot remainedunchanged at Time 2, indicating sustained non-wetting over time.

Materials used in Example 8 include:

-   -   Corning stir plate    -   NFC suspension (2.1 wt % in water)(Auburn University)    -   DI water    -   Revlon blow dryer    -   Hair ties    -   Tape    -   Stirring bar receiver    -   Full Shine Remy human hair: Amazon    -   Sigma Aldrich Chemicals        -   Glycerol        -   Low molecular weight chitosan        -   Hydroxypropylmethyl cellulose (HPMC)        -   Acetic Acid    -   Other chemicals        -   Xiameter OFX-0193 PEG-12 dimethicone: Dow Chemical

Example 8: NFC Hair Hold

This experiment tested the ability of treated NFC to aid in hair holdand replace the use of hairspray and harsh chemicals. An NFC suspension(2.1% concentration) was used in this experiment. A 9.43% solution ofHPMC and glycerol was made, containing 90.57% DI water; a 100 gm stocksolution was made, containing 9.43 grams of HPMC/glycerol (8.96 grams ofHPMC and 0.47 grams of glycerol), and 90.57 g of DI water; thissolution, in which 95% of the actives were HPMC and 5% were glycerol,was the HPMC/glycerol solution used as follows: 5.95 grams of the 2.1%NFC suspension was added to a small beaker, and 3.98 grams of theHPMC/glycerol solution was added in with the NFC suspension, leading toa 3:1 ratio of active dispersant to dry NFC. The suspension was mixed byhand and set aside.

Separately, a 1% low molecular weight chitosan solution was made,comprising NFC in 1% acetic acid. To do this, 40.06 grams of DI waterwas added to the beaker with the NFC suspension (previously treated withthe HPMC/glycerol solution previously prepared) for further dilution.Then, 0.5 grams of acetic acid was added dropwise into the beaker andstirred on a stir plate. 0.5 grams of chitosan powder was slowly addedto the beaker while the suspension stirred vigorously. The suspensionwas left to stir for about an hour until the suspension lookedhomogeneous. Once the chitosan appeared to be fully dissolved, 2.5 gramsof Xiameter OFX-0193 PEG-12 dimethicone from Dow Chemical was added tothe beaker and stirred for a few seconds. This formulation was set asidefor testing as a hair treatment.

The formulation was then tested against a control sample to validateefficacy as a hair treatment. Two samples of 0.5 grams of hair were cutfrom the Full Shine Remy human hair wig. Each sample was cut to be 12inches in length. Each sample was tied at one end with a small hair tieand secured to a table with tape. Each sample of hair was thoroughly wetwith DI water until no dry hair remained. The control hair sample wasleft wet with water only, and the experimental hair sample was then wetwith 0.2 grams of the previously described hair treatment. The hairtreatment was applied with a syringe, and then thoroughly rubbed throughthe length of the hair sample. Both samples were then curled up tightlyaround a stirring bar receiver and blow dried for 3 minutes. After thethree minutes, the stirring receiver was removed from the hair, and thecurls were observed. The curls were also observed after pinching thecurls along the length of hair to stretch them out 3 to 4 times.

Results immediately after blow drying the control and experimentalsamples showed similar curls. Curls were very tight, with ringletsprecisely the size of the diameter of the stirring bar receiver. Thecontrol sample showed strands of hair that were slightly less tight thanthose of the experimental sample, with slightly more space in betweeneach strand of hair. After pinching the hair and stretching it out, thecontrol sample ringlets became farther apart, and did not provide any“bounce back.” The diameter of the ringlets grew to nearly double thesize of the diameter of the stirring bar receiver, and the hair becamefrizzy, with each strand now farther apart from each other. Theexperimental sample bounced back to its original shape, with no changein ringlet diameter, space between the ringlets, or space between hairstrands. All curls from both the control and experimental samples weresoft to the touch with no “crispiness.”

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. An article of manufacture comprising a redispersible dried,nanocellulose-containing material and an active agent, wherein theredispersible, dried, nanocellulose-containing material comprisesembedded nanocellulose elements and a drying/dispersal additive, whereinthe nanocellulose elements are selected from the group consisting ofcrystalline cellulose, cellulose microfibers, cellulose nanofibers, anda combination of cellulose microfibers and cellulose nanofibers, whereinthe drying/dispersal additive inhibits hydrogen bonding of thenanocellulose elements during the drying process and is selected fromthe group consisting of temperature-responsive polymers, small moleculeadditives, and blocking agents, wherein redispersibility of theredispersible dried nanocellulose-containing material is greater thanthe redispersibility of a dried control material that lacks thedrying/dispersal additive but is otherwise substantially identical tothe redispersible dried nanocellulose-containing material, wherein thenanocellulose elements are formed as a matrix, and the matrix is shapedas a support for or a container for an active agent, and wherein theactive agent is a laundry product or a household product.
 2. The articleof claim 1, wherein the drying/dispersal additive is atemperature-responsive polymer.
 3. The article of claim 2, wherein thetemperature-responsive polymer is a lower critical solution temperature(LCST) polymer or a short-chain oligomer derived from the LCST polymer.4. The article of claim 1, wherein the nanocellulose elements are thecombination of cellulose microfibers and cellulose nanofibers.
 5. Thearticle of claim 1, wherein the matrix has been treated with a barriertreatment to impart barrier properties thereto.
 6. The article of claim1, wherein the matrix further comprises a secondary additive.
 7. Thearticle of claim 1, wherein the matrix acts as the support for theactive agent.
 8. The article of claim 7, wherein the active agent ispresent in the interstices of the matrix.
 9. The article of claim 7,wherein the matrix supports a plurality of active agents.
 10. Thearticle of claim 7, wherein the matrix is shaped in a form factorselected from the group consisting of a dried sheet, a gelatinizedsheet, a chip, a ball, a regular or irregular sphere, a cube, arectangle, a cylinder, a plaque and a strip.
 11. The article of claim10, wherein the matrix is shaped as at least one dried sheet.
 12. Thearticle of claim 11, comprising a plurality of dried sheets in a layeredarrangement.
 13. The article of claim 12, wherein the active agent isdispersed on the surface of one or more of the dried sheets in thelayered arrangement.
 14. The article of claim 1, wherein the activeagent is the household product, and the household product is selectedfrom the group consisting of dishwasher soaps, dishwasher treatments,toilet bowl cleaners, oven cleaners, and floor cleaners.
 15. The articleof claim 1, wherein the active agent is the laundry product, and thelaundry product is selected from the group consisting of bleaches,laundry detergents, enzymes, fabric softeners, static reducers, andfragrances.
 16. The article of claim 15, wherein the active agent isselected from the group consisting of laundry detergents, enzymes, andbleaches.
 17. The article of claim 15, wherein the active agent isselected from the group consisting of fabric softeners, static reducers,and fragrances, and wherein the active agent is applied as a waxy layerto the matrix, wherein the waxy layer is capable of melting in a hotdryer to release the active agent from the waxy layer.
 18. The articleof claim 1, wherein the matrix acts as the container for the activeagent.
 19. The article of claim 18, wherein the matrix is formed as asheet that envelopes the active agent.
 20. The article of claim 18,wherein the matrix that acts as the container for the active agent alsoacts as a support for an additional active agent.
 21. The article ofclaim 18, wherein the container is a time-release container or acontainer requiring a preselected water temperature before dissolving.22. The article of claim 18, further comprising a second matrix thatacts as the support for the second active agent.
 23. The article ofclaim 18, comprising a plurality of sheets that form one or moreseparate compartments for one or more active agents.
 24. The article ofclaim 23, wherein the plurality of sheets comprises two sheets that sealtogether to form one separate compartment for one active agent.
 25. Thearticle of claim 23, wherein the one or more separate compartments havedifferent dissolution properties.
 26. A method of producing an articleof manufacture comprising redispersible, dried NC-containing materialwith nanocellulose elements embedded therein and an active agent that isa household product or a laundry product, comprising: providing a liquidformulation comprising a suspension of nanocellulose (NC) elements in aliquid medium, and a drying/dispersal additive, wherein thedrying/dispersal additive is selected from the group consisting oftemperature-responsive polymers, small molecule additives in volatilesystems, and blocking agents; drying the liquid formulation to form theredispersible, dried NC-containing material with nanocellulose elementsembedded therein, wherein the redispersibility of the driedNC-containing material is greater than that of a dried control materialprepared by drying a control suspension of nanocellulose elements in aliquid medium, wherein the control suspension lacks a drying/dispersaladditive, and forming the dried NC-containing material as a matrix thatprovides a support for or a container for the active agent.
 27. Themethod of claim 26, wherein the drying/dispersal additive is atemperature-responsive polymer.
 28. The method of claim 26, wherein thetemperature-responsive polymer is a lower critical solution temperature(LCST) polymer or a short-chain oligomer derived from the LCST polymer.29. The method of claim 26, further comprising a step of forming thematrix as a support for the active agent.
 30. The method of claim 26,further comprising the step of forming the matrix as a container withinwhich the active agent is enclosed or enveloped.